Answers that stretch outside of this time-frame are of course welcome, but I'm just curious as to why these 'free cities' couldn't become 'city states' like Venice, Florence and Milan.
I know they were technically under the sovereignty of the Emperor, but this was minimal authority in practice, and both Milan and Florence were at times under the Emperors authority too.
I'm guessing it was too much competition to allow for the expansion, but I'd love to know details.
Thanks.
The Hanseatic League was around in the time frame you mentioned and contained HRE cities. It was a dominant force in Baltic trade.
The landlocked cities weren't as powerful simply because maritime trade was the name of the game.
Otherwise I'm not sure what exactly you want to know.
access to the Meditteranean was also an important factor. Particularly when we look at the lucrative trade in spices which travelled to Italy via the Silk Road. Cities like Venice were nearly completely built on trading in exotic goods from the Silk Road and Meditteranean area.
This is a trade which the HRE simply did not have access too without going through Italy first.
The advent of the 'Atlantic World' in the 16th-17th century would cause the Italian States to enter relative decline (when we compare their economies with the powerhouses which were the Dutch Republic, and later England.)