List all the years mentioned in the following passage

Context: During the Middle Ages, the Gran Tavola was the largest Sienese bank; it was one of the most powerful banks in Europe from 1255 to 1298. The Gran Tavola has been called "the greatest bank of the thirteenth century" as well as "one of the largest commercial and banking enterprises in Europe".

The main branches of the Gran Tavola during the mid-thirteenth century were in Pisa, Bologna, Genoa, Marseille, and Paris.

Answer: 1255, 1298