There’s something a touch wild about Belgrade. The mighty Kalemegdan Fortress perches on a rock overlooking the place where the Danube meets the Sava River. Much occupied and much conquered, it has seen Celts, Thracians, Illyrians, Romans, Avars, Byzantines, Slavs and Ottmans come and go over the years. In all of Europe there may be places more fought-over, but none so recent: the Ministry of Defence building still stands ruined, destroyed by NATO bombs in the 1990s.

Kalemegdan is just the most visible sign of this frontier mentality. For Romans, the Danube was the dividing line between the civilised world and the barbarian sphere, from whence strange tribes would occasionally emerge to threaten and then perhaps join with Rome. With nomadism as a way of life now mostly disappeared, that doesn’t seem to happen as much any more, but there are still forces that will lead people to travel vast distances: I saw more refugees in Belgrade than I did in Budapest, clustered around the train and bus stations.
 

 
When the Danube was both frontier and highway, controlling it was vital. Kalemegdan played a part in that, but the even larger (if less well preserved) Smederevo Fortress a few miles down the road served the same purpose. It’s unusual among the fortifications that I’ve seen in this part of the world in that it’s not built on a hill but instead on the banks of the Danube itself. This lack of a solid rock foundation may explain why some of its walls and towers tilt alarmingly far from the vertical – the forces of time and tide tear down everything that is built sooner or later.

Back in Kalemegdan though, the Museum of Military History offers a fine collection of tanks and artillery outside (packed into the fort’s defensive ditches alongside tennis and basketball courts) and a potted history of Serbia’s story told through war. Very little of what is told is set out in English, but the multiple maps of the area with arrows heading this way and that make it quite clear: armies have been marching hither and thither across Serbia for as long as records have been kept.
 

 
Upstairs in the museum, things get more interesting, as the story turns to World War II, Yugoslavia and Tito. Serbia, of course, was once at the heart of Yugoslavia, back when the map of Eastern Europe looked a lot simpler than it does now. As with the rest of Eastern Europe, Yugoslavia fell under the Soviet Sphere of influence, but it forged a path of its own under the guidance of Josep Broz Tito.

I don’t know enough about the man to judge him, but he’s obviously still revered in these parts, and what I do know is fascinating. Famously, after he’d fallen out with Stalin, he endured several assassination attempts before sending a tetchy message: “Stop sending assassins. I’ve already caught three. If you don’t stop, I’ll send one myself and I won’t have to send another.” True or not, it’s become part of the national folklore, and the museum, especially in the latter half, builds to the reveal of a shrine to Tito.

There’s an addendum, of course. Those NATO airstrikes still rankle, and the museum makes clear whom it thinks the aggressors were, mapping the countries to blame right beside the fragments of an F-117 stealth fighter-bomber shot down over Serbia. Wars become history just as quickly here as they do anywhere else.