Visconti was the family name of two important Italian noble ynasties of the Middle Ages. Two distinct Visconti families are known: the first one (chronologically) in the Republic of Pisa in the mid twelfth century, who achieved prominence first in Pisa, then in Sardinia, where they became rulers of Gallura; the second and most important one rose to power in Milan, where they left a permanent historical mark ruling the city from 1277 to 1447 and leaving several collateral branches still extant.