It is located in Piazza delle Erbe. On a pre-existing covered loggia built in 1347, the Belluno branch of the Cadore family, the Costantinis, erected their palace between 1471 (as evidenced by the coat of arms of the Venetian rector Benedetto Priuli carved on the capital of the corner column) and 1473 (coat of arms of the rector Antonio Basadonna on the façade), while maintaining the large open porticoed space on the ground floor where the Ghibelline faction, that is, pro-imperial, traditionally gathered, which gave its name to the entire palace.
Perhaps for this reason, in July 1509, it was here that Emperor Maximilian of Habsburg lived for a few days during his only stay in Belluno during the Cambrian Wars.
After Belluno was reconquered, Venice symbolically placed a large lion of St. Mark here in 1517, to reaffirm its renewed possession of the city and to contrast with the other Venetian lion, which was carved on the die of the nearby fountain, sculpted by the imperial troops and which Venice left damaged as a future reminder of the vandalism suffered. In turn, the same fate also befell the lion of Palazzo Costantini, which was destroyed by hammer blows by the Jacobins in May 1797.
