I was listening to the In Our Time podcast on the Icelandic Sagas, and got to thinking about the medieval Icelandic economy. Iceland just doesn't seem like a particularly productive landscape. While they probably had no shortages of wool, leather, or stone, it seems to be short of both the ability to cultivate a main staple starch and of wood. Was this the case in the medieval (warmer?) period? Were they reliant on wood or grain from Norway or elsewhere? What about minerals? Could Icelanders produce their own iron weapons and tools, or did those have to be imported?
Iceland was highly dependent on trade with the outside world. The most common exports were stockfish and vaðmál during the Medieval period.
Through trade with English and German sailors, Iceland got:
See this PDF for some information on Iceland's trade relations during the 15th century.