This would have delighted QMII!!
Not only the performance but also the place itself.
Fyrkat is a ringborg = circular castle from the Viking Age, actually from the age of Harald Bluetooth, the son of the first official king of Denmark and as such the second in the direct line of succession that now see Frederik X on the throne. Harald Bluetooth (probably because he had a rotten fronth-tooth) is is officially credited with Christening DK. That one may be a slightly exaggerated though. Denmark wasn't really thoroughly Christian until around 1200. But officially declaring DK Christian saved the kingdom from an invasion from the Carolingians, who at that time were very busy force-Christening the lands just south of Denmark.
Anyway, Harald Bluetooth had five (that we know off, probably more) circular castles made in various parts of the kingdom.
They consisted as you can see in the photos below of a circular earthen rampart with a palisade on top and a moat in from of the ramparts. There were also four entrances and the castle was divided into four sections with several buildings in each section. It was and is a geometric marvel and it would have taken less than half an hour to stake out the entire plan for the castle and then it was a matter of building it.
It looks very much like a local adaption of a Roman marching camp, and it may very well be just that.
I doubt very much that one day someone came up with the thought: Let's build a geometric castle! I strongly suspect such smaller castles were build for centuries before these were build in the late 900s.
Interestingly, big as they are, and these castles are
big! They were only in use for a few decades and most of the time there would only have been a skeleton garrison there. So it's assumed that they were not means as fortresses, except in emergencies, but as local mustering points.
All free men were required to arm themselves and come to the defense of the kingdom if the king called: mand af hus = man of house = general mobilization. In fact that was the definition of a free man, who had a voice in the local ting = council.
So when the call came, perhaps by bonfires or a fast ship. The local men of that particular region would don the armor and get their weapons and rush (most likely by boats) to the nearest circle-castle. Here they would train fighting in formations and when most had gathered they would, under the command of either a local lord or one the king's earls (jarl) and board the longships that were also stored near such a ring-castle and join the king.
In Denmark armies didn't march, they sailed. The reason being that there was basically only one road in the whole kingdom suitable for a marching and that road is to this day called Hærvejen = the Army-Road, it goes all along the Jutland peninsula, and that road too was a local imitation, albeit much more primitive, of the Roman roads. The people living outside the Roman empire observed, learned and adapted.
That is also the main reason why Denmark has never been conquered. DK then as now consists mainly of islands and parts of land separated by straits. So when an invading army marched up through Jutland, and that happened a number of times, that army would always find itself cut off by a Danish army that had sailed in and landed behind them. Usually ending the conflict.
But back to the ring-castles.
Here is Fyrkat, which QMII visited as it looks today:
Here is a larger circle-castle:
Here is Fyrkat reconstructed:
And finally a reconstructed long-house. Which would have been a barrack or a communal hall for eating and meetings, a stable for horses (horses in the Viking Age were smaller than the war-mounts just a couple of centuries later), storage, workshop, smithy, shops for the ship-builders etc.
Notice that at this time there were no such thing as chimneys. The smoke exited through the vents at the end of the buildings.
Also note: The longhouse would have predated the flag, Dannebrog, by only 250 years, almost to the date.
Now, these castles weren't build just for fun. There must have been a threat against Denmark, most likely either from an invader in the south, the Carolingians. Or serious Viking raids coming out from Norway or western Sweden. Denmark at the time was a relatively prosperous kingdom with a lot of trade, getting even richer with some seriously organized Viking raids of our own, mainly towards England and northern France, so it's also likely that these castles were meant as mustering points for a regular and highly organized invasion. Or they may have been means as defenses against raiders coming from what is now eastern Germany, they a serious menace in the 11-1200s until the Valdemars whacked them! As in invading and seriously and thoroughly bashing their heads in and Christening the survivors - except for those that could be sold as slaves via the trade routes to Constantinople of course.
The Christian countries couldn't buy Christian slaves, but they could and certainly did buy heathen slaves. - No problem. You want heathens, we've got 'em! Christian captives were either sold to heathen kingdoms or shipped off to Constantinople or in many cases bought back by Christian kings - who earned some brownie-points with God that way.
So an English boy captured in Kent could easily end up in the general area of Bulgaria or even Isfahan in Iran - if he survived the journey. The Nordic way of dealing with sick people when traveling was quite simple: They were isolated with a couple of slaves (thralls) to look after them. If they survived, they went with the next shipment on the route, if not, too bad. The building they were in and where they died, was burned - problem solved.
And that is exactly what would have happened while these castles stood.
Also, it took a strong power to organize, fund and persuade people to build and man these castles, which means that Harald Bluetooth was in firm control of his kingdom. And some scholars believe that Harald Bluetooth as such was the first true king of all of Denmark. - Which is probably not correct, because there are very clear evidence of Denmark being a organized kingdom under a central power for at least periods in the centuries up to the Viking Age.
- So QMII was absolutely in her right element at Fyrkat!