Ok, I searched for Poland and Hamburg and nothing came up, so here is my question.
I am playing Poland, early era, 2.5.1, H/VH, UAi 1.6. Its 1109 and I have Hamburg. Is there any point in keeping it a fort, as with the recruitment system I am unable to recruit troops here. It seems that Magdeburg is far more useful and converting Hamburg to a city will at least give me some troops and as the Ai never converts would deny it to HRE if they ever take it back.