What does You must send back any allied armies garrisoned within your city before you can teleport your city mean in Evony?

In Evony, the statement means that if your city has allied armies stationed there, you need to remove them before you can use the teleportation feature to relocate your city. This restriction is in place to ensure that all allied forces are returned to their respective owners, maintaining the game's balance and strategy. Essentially, it emphasizes the importance of managing troop placements before executing a city teleport.