Not far from where I live is the narrow shipping passage of Baggensstäket, famous for a skirmish against the Russian coastal fleet in 1719. Less well known is the place's importance as a military and communicative hotspot in the Viking Period. Ships sailing into Lake Mälaren have gone this way for over a millennium and the route is documented in writing from the 13th century onward. On either side of the narrowest passage is the heaviest concentration of Viking Period (9th and 10th century) pagan graves for several miles around. The mounds and stone settings (and, before that, the cremation pyres) were clearly placed in order to be seen from a boat. Some were even on a little islet at the time.
An 11th century rune stone (badly incomplete: the only legible word is "and", as in the formulaic "YYY and ZZZ erected the stone after NNN, their father, a very good man") has been found on the north shore at the High Medieval manor of Boo. And this brings us to the place names.
Boo is typical for re-named High Medieval manors -- a bo was the administrative centre of a land estate. This one was probably called Harg before that, meaning "pagan altar", heargh in Old English, Harrow in modern English place-names. And late 1st millennium Scandinavian pagan cult was dominated by the aristocracy. So place name and rune stone document the presence of Viking Period bigwigs.
Then there's the name Baggensstäket (once the stäk of Harg). Stäk means shipping blockade, underwater palisade. No remains of the actual blockade have been found, because the passage has been dredged repeatedly through the centuries.
As I have argued in Nackaboken 2003, all of this indicates that Boo manor's predecessor and the blockade was part of the early town Birka's peripheral defence in the 10th century. A high-ranking henchman of the king of the Svear appears to have been stationed here with a military detachment to guard the blockade. These men and their families very likely rest in the abundant graves.
Tomorrow, I'll be metal detecting for a small excavation project designed to find more pieces of this jigsaw puzzle.
My friend and mentor Jan Peder Lamm has a summer house not far from Boo manor. In his garden is a mound-like feature full of Late Medieval bricks. Intricately shaped bricks, not the garden variety, and many of them badly warped and blackened by fire. This thing must have been either a brick kiln or a pretty ostentatious brick building -- perhaps a defensive structure. Either way, it's further evidence of bigwigs. We all look forward to learning more!
[More blog entries about Viking Period, Vikings, archaeology, Sweden; vikingatiden, medeltiden, arkeologi, Nacka.]