Ancient civilisations on the baltic?

is it possible to have non-tribal civilisations - city states, empires, maybe republics - along the coast of the baltic in ancient times? there is ample trading to be made from amber in the area, but weather is difficult and the tech to sustain high populations didn't reach the area until much later.

But could it be done? Who would be the peoples in this baltic ancient world (proto-scandinavians? sami peoples? proto-finns?)? how does it impact things further south?
 
The main problems are that land around the Baltic have low biodiversity and it’s marginal land for the Eurasian crop packet on the edge of where it’s viable to use that packet. So the early Eurasian crop packet need a lot of time to adapt to the region and improvements in agricultural technics and technology, and there’s a low limit in local domesticable plants.
 
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