They belonged to the Morcote branch of the Fossati, a prominent Ticinese family with mentions in the historical record going back to the 14th century.

[1] The brothers finished primary and middle school in Venice and studied architecture at the Brera Academy in Milan.

The Fossati brothers' time in Constantinople would mark the beginning of a very productiver period, and Gaspare would enjoy a distinguished career there.

[3] Between 1841 and 1843, the Fossati brothers built the brick Bab-ı Seraskeri Hospital (Bekirağa Bölüğü) and Liman İskelesi Karakolu in Eminönü for the Ottoman Administration.

[5] Sultan Abdülmecid allowed the brothers to also document any mosaics they might discover during this process which were later archived in Swiss libraries.

Upon the death of Reşit Paşa in 1858, the Fossati brothers built his mausoleum in the corner of the graveyard in the Bayezit complex.