The Morosini are an ancient Venetian patrician family. and the origins of this family are uncertain, but certainly very old. A first legend states that Morosini had arrived in Laguna, fleeing from Attila; a second, on the other hand, considers them to be from Mantua. All traditions, however, agree in placing it among the twelve apostolic families who participated in the election of the first doge Paolo Lucio Anafesto.
They were involved in Venetian public life since the eleventh century and were distinguished until the end of the Serenissima by giving four doges, four Dogaressa, twenty-six procurators of San Marco and politicians, joined by traders, industrialists, men of arms and prelates (among which three cardinals and the first Catholic patriarch of Constantinople). The family's interests were also extended abroad thanks to marriages between Tomasina Morosini and Prince Stephen of Hungary and between Constance and Stephen Vladislav II.
In 1819 they were awarded the title count by the Austrian Empire, in 1890 also recognized by the Kingdom of Italy.
Of the Morosini various branches were distinguished: the Morosini "of San Polo", "in Canonica" and "of the Santi Apostoli" still flourish, while the lines "di Santo Stefano", "di San Tomà", "dei Santi Giovanni e Paolo "e" of San Polo sul Ponte ".