Farewell to Landsjö

On Friday, we finished the 2015 excavation season by filling our trenches at Landsjö. With everyone working hard in the mild, morning weather, we finished before lunch time. We ate one last meal together in the ballroom at Landsjö, and then everyone scattered throughout Sweden to finish the summer. I'm back at Cambridge now, putting the finishing touches on my master's degree, and I'll head back to California for a month of rest at the beginning of September.

Finds of the Week #3

Today is our last day digging for the 2015 Stensö/Landsjö Excavation Season. We will mostly be filling the trenches that remain open, returning tools to the local museum, and cleaning the house. However, this week we made several awesome finds.

In Trench I, inside the southwestern tower room, identified as a cellar of some sort, we finally cleared all the rubble after five days of digging. Once the layer under the rubble was excavated, a huge quantity of items were uncovered, including the huge key shown below. Keys are a fairly common find on medieval sites, some even larger than this one. This one was found in-situ with a hinge (also visible in the photo) and a large amount of bone, suggesting it is part of a rubbish heap left behind when scavengers ripped out a flagged floor, pieces of which they left, inside the tower.

A key found in Trench I, Landsjö.

We also found this copper-alloy dress ornament in the shape of a rose. This probably would have been sewn onto a man's tunic or onto a woman's dress. We found several other personal items as well (not pictured) including part of a comb and a knight's spur.

A copper-alloy rose.

Even though the dig is over, I still have some posts to put up about it in the future.

Allemansrätten

Chanterelle mushrooms picked in the forest near Landsjö. 

In Sweden, one has the right to roam on private lands without permission. Called the Right of Public Access (Allrmansrätten), it includes the ability to forage on private lands, except for the private area immediately surrounding a dwelling.  That means mushrooms! This weekend, we went into the forest nearby and gathered wild chanterelles. They grow abundantly in the summer and autumn in Sweden, particularly after bouts of rain  like we've just had. There are no similar looking species of mushrooms, except for another, less tasty type of chanterelle, and it's perfectly safe to gather the bright, yellow mushrooms. You can never have too many chanterelles. 

Finds of the Week #2

Work has been slow at Landsjö this week; we lost an entire day to hard rain and thunder storms and several of the students have been ill. However, we have still had a couple of extraordinary finds.

A  type of medieval ard found while searching for the bridge that connected Landsjö Castle to the shore.

While trenching to find the bridge that would have connected Landsjö to the shore, I recommended that one of the students metal detect the dirt we temporarily removed. This was no small task given that the pile contained around 200 cubic meters of mud. Just before finishing, Ola uncovered the head from a medieval ard, something used for ploughing, similar to maul or hoe. The tool has been made with several design decisions such as the angle and type of socket used to haft it, and it will therefore be easy to date typologically. Although at first we thought it was from the Bronze Age, we are now fairly certain it is high medieval. 

The other side.

However, the most specular find from the week, in my opinion, is a small piece of ceramic we found in Trench H. Team H has been looking for evidence of a drawbridge or other structure in the vicinity of the dry moat that divides the island in half near the southern edge of the perimeter wall. Although no evidence of this type has been or will be found, we are fairly certain the trench shows evidence for the excavation of the moat. The piece of ceramic, which is quite thick and made from a paste with large quartzite fragments and decorated with a stamp, is almost certainty from the Swedish Battle Axe Culture, a subset of the Corded Ware culture that existed throughout Europe in the late Neolithic. This would make the ceramic at least 4,000 years old—more than 3,200 years older than anything else we have found on the excavation thus far. It is likely that while digging the ditch, the medieval workers displaced the remains of a Neolithic settlement on the island. A few centimeters below the Neolithic ceramic, a piece of medieval ceramic was also recovered, illustrating the feasibility of this explanation.

A piece of  Swedish Battle Axe Culture ceramic uncovered in Trench H at Landsjö. 

After finding the ceramic, we have screened with extra vigilance, looking for prehistoric artifacts that can be easily overlooked when searching for medieval remains. Other than flint and whetstones, most rocks are considered geological and not worth a second glance in a medieval setting—not so when dealing with stone age culture. Since then, we have found fire-cracked stones and many pieces of quartz debritage—the remains of stone tool manufacturing or knapping. These finds show that Landsjö has been inhabited far longer than anyone previously realized. 

This week, as we finish digging inside both the northwest and southwest towers of the castle, we hope to make many more finds. 

Bridges and Dendrochronology Dates

Excavating for a bridge at Landsjö, on an industrial scale (photograph by Simon Terbrant Säfström).

Because Landsjö Castle was built of incredibly heavy materials (the mortar alone would have required tons of sand and limestone) on an island, we always assumed that it was accessed from the shore via a long causeway or bridge. Although we know the castle was deconstructed over successive winters by dragging the large stone blocks across the ice sometime in the 1500s and 1600s, such a methodology would have been impractical for building the castle during short, winter days. 

Our initial idea was confirmed last year when we found used horseshoe nails intermixed with debris from the construction of the castle in Trench D. Although horses can swim and although they may have arrived on a barge, it seemed likely they came across a bridge. 

Two of the students, Henrik and Daniel,  enjoying the muddy work.

This year, we applied to dig a 1.5m x 150m trench in cooperation with the landowner Micke whose house we stay in during the dig. His foreman drove the digger out today, and we began the enormous trench. At our current numbers and pace, it would take us seven months to dig as much as he accomplished in a few hours. 

Posts retrieved from the trench. Note the tapered ends on the right two stakes. All three are probably large enough for dendro dates (photograph by Simon Terbrant Säfström).

The results were spectacular. By searching in the trench for the posts broken off as the trench was excavated, we were able to retrieve 15 or so, three of which can probably be dated using dendrochronology to the nearest-decade—if not the exact year—the tree was cut. Dendrochronology is ostensibly the science of quantifying tree rings based on large, known assemblages of preserved wood. In the waterlogged, oxygen-poor mud near the lake, organic materials do not degrade quickly, and there is a chance the posts may be even older than the medieval period.

The smaller pieces that cannot be dated using dendrochronology can still have their intrinsic ages determined using radio-carbon dating. Thus, the assemblage of posts we recovered, slices of which are now resting in the large freezer downstairs until they can be moved to a lab, is invaluable in determining the construction sequence of the castle. There was another spectacular find made along with the posts, but you’ll have to check back tomorrow for more on that.

Part of the full assemblage of posts recovered.

Abandon Ship!

Although we've been very lucky with the weather so far—rain tends to be less frequent in Sweden during late June and all of July—today we had a really wet day. With thunderstorms forecast about half an hour after the video below was shot (and indeed they did come) we decided to make a hasty retreat back across the lake. Later, after lunch, with the sun shining we set out to return, but only made it to the boats before the sky turned dark and the thunder started again. Better luck tomorrow...

Photogrammetry

Simon getting an aerial view from a tree.

Following on last year, I've been using photogrammetric models to obtain orthogonal aerial views (taken at a 180º angle looking down onto the trenches). Photogrammetric software estimates the three-dimensional coordinates of an object (in this case an excavation unit), by making measurements between objects present in multiple photographs. From a cloud of photographs taken at different angles and heights (the model below uses 47 different views), I am able to obtain a perfect aerial shot—though there are other applications as well.

Photogrammetric model of Trench F, Stensö. Although only the aerial view is visible here, the model is fully 3D and can be viewed from any angle. 

Archaeologists traditionally had to resort to all kinds of methods for aerial photography—from balloons to ladders to heavy gantries for lifting up a camera. This method, which uses the Russian software Agisoft, is quite simple and only requires a camera on site. Both high and low angle views are desirable, though not strictly necessary—at Stensö we can stand on the tower to get high angle shots, and at Landsjö we can use the trees.  These shots do not have to be directly overhead. Back at the dig house, the photos need to be carefully cropped to remove areas outside the area of interest (trees, for instance) and any elements that are not in focus.

Trench F, Stensö, drawn.

From there, I am able to use the models later on for drawing or for direct documentation in the report. The drawing above was made using a series of photogrammetric models documenting the excavation of the first 20cm of Trench F at Stensö. Although drawings like this can also be done by making what is basically a downward facing photographic panorama, this actually takes less time. I also think it represents shapes better than the panoramic method. Photogrammetry is a great digital method for archaeology. 

Life on the Dig

Lunch on the site at Stensö on a sunny day.

The crew eating dinner at our Stensö accommodations at Smedstorp farmstead.

Playing a game at Landsjö manor, where we stay for the second two weeks.

The wood-fired hot tub at Smedstorp.

My co-director Martin surveying the ruined perimeter wall at Landsjö.

Landsjö

Landsjön at sunset.

On Friday we finished at Stensö and made the move to Landsjö, a little to the west. Although the other trenches were closed on Wednesday, Trench F, inside the tower at Stensö, was not finished until Thursday evening. With such a large crew this year (15 as of this morning), we're moving faster than last year. We'll see what we find here...

In The End

A 2015 ten-pence piece.

In best archaeological practice, we excavate to the point where archaeology becomes quaternary geology. Depending upon how limited our time and how ambitious our goals have been, this may or may not occur, but it is always a shame to close a trench before reaching what is termed “the Natural” level. 

Today in Trench F, we reached a deep fissure in the bedrock against the wall of the tower, which despite containing fragments of brick, was judged to be below the deepest level in which we were likely to still recover more finds given the large amounts of unmixed, blueish-gray glacial clay constituting the layer. Therefore, we closed the trench by backfilling.

Before backfilling though, we always “salt” the trenches with modern coins. For two weeks before the excavation, I carefully went through my change in Cambridge and pulled out all the low-denomination, 2015 coins for this purpose. Swedish coins were added as well. The purpose—half in jest—is that if any future archaeologist excavates in the tower again but has not read the report for whatever reason or has chosen to re-excavate because they believed we missed something (both of which occur from time to time), they will find evidence of the deepest level we reached. 

However, this is fantastically unlikely to occur. On a philosophical level, the coins will rest just above the bedrock under the tower at Stensö until the end of time. They are, in the larger scope, some of the only things I ever possessed that I know the location of, precisely and definitively, in time after my death. And after I cease to know that, well, they’ll be just like everything else: an artifact that in the absence of a historical record—and even then—will never, under all powers of scientific scrutiny, reveal my identity. 

Coins and backfill aside, that’s the archaeological conundrum. As W.G. Sebald wrote in The Rings of Saturn, paraphrasing the East Anglian antiquarian Thomas Browne,  “We study the order of things… but we cannot grasp their innermost essence. And because it is so, it befits our philosophy to be writ small.”

Medieval Man's Best Friend

A paw print found on one of the bricks at Stensö.

Sometime in the 1300s, a brickmaker had just finished laying out the still-moist forms of future bricks, ready to be fired, when a dog ran through her work. Some 700 years later, we uncovered evidence of that canine romp, because apparently it wasn't enough of an issue to warrant a do-over. Undoubtedly, other bricks were marked similarly—the dog didn't just step on one brick. I can just imagine how guilty it must have looked when it got yelled at.

It's actually somewhat common to find animal and human prints on archaeological sites and materials, but this is the first time I've seen it with a dog. Strangely, the piece of brick is harder than most and seems to have survived because of how the paw print distributed the heat during the firing process. Neat!

Finds of the Past Week

This week, in addition to several kilos of animal bone—ubiquitous on medieval sites, and useful for understanding past subsistence—we made some special finds.

An iron crossbow bolt and arrowhead uncovered in Trench F inside the tower, testaments to the martial nature of castles like Stensö.

In Trench F, inside the tower, we found two weapons, both projectiles. The first, above on the left, is the bolt from a crossbow. Skulls with wounds from bolts such as this have been found in the mass grave on the site of the great battle between Valdemar Atterdag’s Danish armies and the people of Gotland. Crossbows were a truly horrific weapon.

The smaller find beside the crossbow bolt is a normal arrow head, still quite deadly.

An annular brooch uncovered in Trench D.

In Trench D, one of the students uncovered a silver or copper alloy brooch (we wont be certain until it is restored). An exact correlate in type to this brooch was recovered from a hoard that was dated very precisely using coins in the hoard, giving us a very exact idea of when brooches such as this would have been extant in circulation. Much like the brooch we found last year at Stensö, it’s a great find. When we find possessions like these, I always wonder how they came to be lost. Was it swept out with the rushes by mistake? Did it fall from someone’s cloak while riding? In any case, brooches are great for establishing dates.

The wealth of ceramic sherds we have recovered this week, although not as photogenic as some of the special finds, are also very useful for dating the layers in which they occur. Ceramic from this period provides a 100 to 200 year window for dating, and this can be refined even further if larger, diagnostic sherds are excavated. These finds, such as the rims of a particular pot or vessel, can narrow dating to as little as 25 years—exceptional.

Thus far, we have still not found any coins, the ultimate diagnostic for dating. However, with the living floor identified inside the tower, we should rectify this soon if we are lucky. Finds such as these—although they can be deposited or lost long after they have gone out of circulation—are even better than getting a radio-carbon date. Cross your fingers for us…

A runic inscription in the mortar of the castle, situated behind, but probably not related to, a pile of bricks someone scavenged after the abandonment of the castle.

However, above is the most special find of the week. It is a runic inscription, once written in the still-wet mortar of the castle, which phonetically reads “HELK(I),” a man’s name. Individuals are rarely visible in the archaeological record—though they commonly occur in the historical record. But in this case, we can see and identify a reference to a person who once lived. We can surmise, though not definitely, that Helgi worked on the castle during a repair phase and wrote his name into his work. It is unusual that he chose to use runes which had largely passed out of fashion except in churches by the time the castle was in use. If he had skill as a building craftsman, it is not out of the question that he also worked on other buildings in the area, including churches. 

Start of 2015 Excavations

The map of the 2014 and 2015 excavation trenches at Stensö, Östergotland.

This week we started our excavations at Stensö by opening three trenches inside the site of the former castle and several, smaller exploratory units farther afield. Much like last year, the aims of the project are to retrieve small finds to help better understand how the people of Stensö lived and to uncover architectural features of the castle in order to learn how the castle was built and what form it might have taken while it was in use.

The three main trenches we opened (as you can see on the map) are D, E, and F, with the small group of test trenches labeled G (off the map, farther down the hill near the “harbor” to the east).

Trench D aims to uncover evidence of a well or water catchment area identified in previous surveys by Christian Lovén, the Swedish castellologist, located near the perimeter wall. This site has already yielded an enormous quantity of bone and other waste including iron and ceramic.

Trench E aims to uncover the base of the southern tower wall where it touches the bedrock in order to learn how the castle was built.

Trench F, inside the southern tower, has both architectural aims and aims associated with understanding the lives of the people who lived at Stensö.

Test trenches G (1, 2, 3, 4, and 5) will hopefully show traffic between the castle and the bay, potentially showing how construction materials and other commodities were transported either during the tenure of the castle or during its dismantlement.

I am supervising Trench F, inside the tower. Interestingly, the castle has attracted an enormous amount of attention after it was inhabited and abandoned, and the first layer of Trench F (the turf overlaying the rubble from the collapse), shows clear evidence of camping and other outdoor recreation at the site in the 20th and 21st centuries (a fire ring, melted bottles, bottle tops, clay pigeons, and such). We even found a coin from 1987. Also, thus far, we have uncovered more than 30 1940s era magnesium batteries, showing that the tower was potentially used as a lookout during World War II when Sweden—although neutral in the war—was wary of activity in the region from both Russia and Germany.

Last year, we also found evidence of post-abandonment refuse, potentially dating to when the site was inhabited by tenant farmers living in a small hut or house on the site of Trench C. Thus, although the primary aim of the project is to learn about life in the medieval era, we are also gaining insight into how the site has been used throughout all the eras since. 

The collapse layer at Stensö, showing the bedrock just under the photo scale and the living floor, a thin, dark layer visible just to the right of the complete bricks.

After opening a test trench within Trench F to understand how deeply the rubble covers the cultural layers we are most keen to excavate, we found the “living,” earthen floor of the castle tower immediately overlying the bedrock hill upon which the tower was constructed. As we clear the tower of debris, we will come closer to our aim. Excavating in rubble is often a messy business, much less orderly than working with clear strata one might see in an archaeological textbook. However, since last year we have learned an enormous amount about how the castle collapsed after its use, and seeing a modern collapse at Stegeborg Castle to the south has helped as well. We are moving much more quickly than last year with the help of Martin’s excellent students!

Stensö and Landsjö

The remains of Landsjö Castle. The south-western corner of the outer perimeter wall, ensconced in the roots of a pine tree.

Stënso and Landsjö, although disparate sites and although constructed differently from one another, are remarkably similar in several important ways. 

Firstly, when they were constructed—Stensö slightly earlier than Landsjö—they were both owned by the same family. From the sparse historical records available at the time, we know that Holmger Torkelsson of the Boat family, and his wife Sigrid Karlsdotter of the Stubbe family, lived at Landsjö sometime around 1369 CE. Stensö had been owned by Lord Holmger's great-grandmother, Lady Kristina, sometime around 1280 CE. 

Lord Holmger and Lady Kristina's family probably had good relations with the Swedish crown at the time the two castles were built. In order to build private fortifications, one needed royal permission—specifically a "license to crennelate." Whether the issuing (or forbearance of issuing)  licenses indicated an interest in controlling the spread of military assets or were a way to control the socially ambitious who wished to demonstrate their status through castle building is not entirely agreed upon by archaeologists and castellologists—it needn't necessarily be clear cut. Although licenses to crennelate were rarely refused in England—indicating the crown probably had very little control over whether castles were built or not—the situation in Sweden may not be a direct correlate. The structures of the monarchies in England and in Sweden were different, for instance.

Secondly, continuing with the similarities, both Stensö and Lansjö were originally located on islands. Landsjö currently stands on an island in Lake Lansjön, and Stensö would have been on an island in a marsh in the Bråviken, a Baltic bay to the south of Stockholm. However, today Stensö is firmly landlocked on account of rising land, an effect still felt long since the glaciers receded after the last glacial maximum. Both castles were very difficult to get at if the owners did not want visitors.

Yet however strongly fortified their positions, both castles share a further similarly of meeting what we assume to have been somewhat grisly ends. Both Stensö and Landsjö were abandoned sometime in the 1400s or earlier, and today very little of the stone once contained in their massive walls can still be found on the sites themselves. At Stensö, only the foundation of a round tower and part of a perimeter wall exist above ground, and at Landsjö even less remains—only the western stretch of its perimeter wall, never at a height more than a meter or so, and its northern and southern corners. 
Most of it has been carted away and used to build other, newer structures that dot the local landscape. Stensö in particular shows strong evidence that it once suffered a powerful fire. Our excavations in 2014 uncovered evidence of brick that had gotten so hot it had vitrified, or turned to glass and partially melted under extreme heat. Both also seem to have been abandoned or given over to tenant farmers around the time the plague was spreading throughout Sweden, and this could have played a role in their demise as well.

Both castles are also prime examples of private fortifications—owned neither by the crown, nor by the church. As such, they are somewhat rare, and until our first season of excavations last summer, neither had ever been excavated before. 

I'll attempt to write more about the excavation of these two structures in the coming weeks, but unfortunately we have no internet at our dig house at Stensö, so it won't be as frequent as I would like!

Welcome!

The remaining tower at the Stensö castle ruin, June 2014.

I'm Ethan, and I am PhD student in archaeology at the University of Cambridge. I started this blog to share the excavation I'll be co-directing this year with my Swedish colleague Martin Rundkvist. We start our second season digging with Martin's students from Umeå University at Stensö on Monday, June 22 and at Landsjö on July 6. In the mean time, the excavation reports from our first season can be found on my Academia profile, and please be sure to check out my homepage as well.