Quote Originally Posted by Emperor Umeu 1
yes just build an army and just put it on the bridge
And pay the enormous maintenance for it if you're keeping it there. I don't know about you but I build armies to go around conqering stuff, not sit around on their arses near bridges, stealing the locals chickens and harrassing their womenfolk

Forts are excellent for guarding frontiers, just build them, stick them at choke points with a unit of town guards inside and presto!

They prevent an enemy from rushing into your territory and besieging your cities by holding up an enemy army long enough for you to send an army to lift the siege and deal with them.

This keeps enemies off your land.

They also act as watchtowers of a sort and help to discourage the formation of bandits in the area.

As for the thread question it depends, if the other side of the bridge is someone elses territory (someone I'm not at war with) then putting a fort there would be a trangression. Otherwise yes I prefer to place them on the far side as it allows me to just stick my relieving army on the bridge where the enemy can still reach them, thus forcing the enemy into a bridge battle where I'm the defender.

Though there is one annoying bridge on the map, between Thrace and Tribus Getae where you can't stick a fort on the southside of the bridge despite it being perfectly flat/non-swampy, oh well.