The study presents the Florentine Samily of the Peronis whose first two representatives had settled in Piran in the eighties of the 13th century. By way of preserved and published sources the article is following the lives of the Peronis, their family connections, their descendants, the growth of their business, their pecuniary circumstances) and their social reputation. After the exceptional business success of the first Peronis their descendants in the second half of the thirties of the 14th century no longer belonged among the most successful businessmen of Piran.