site of famous battle

[Centurio Nixalsverdrus]

Never mind. It's a bit tricky. It would be more correct to say that a marker can only appear when the battle was fought on a tile different from the city tile. For example

1. Mak army besieges Rome. Roman army A is approaching from behind and attacks the Mak army. Roman army B from inside the city comes to help, the Maks obtain a heroic victory (what else) - marker will be spawned because the battle will be fought on a tile outside the city of Rome.

2. Mak army besieges Rome. Roman army A is approaching from behind. Roman army B from inside Rome attacks the Mak army, Roman army A comes to help, the Maks obtain a heroic victory (again, what else) - no marker because the battle will be fought on the map of the city of Rome.