Descended from the painter Antonio Busca, he belonged to a noble Milanese family.
[1] The Lieutenant was the head of the Order in the absence of a Grand Master (who would not be elected until 1879).
In June 1821 Busca visited the Order's headquarters, the Convent, in Catania, Sicily.
[2] Like Andrea Di Giovanni y Centellés, his predecessor as Lieutenant, Busca unsuccessfully attempted to have the island of Malta returned to the Order's control.
The Order's administration was then based in Catania, too far from the centres of European power and exposed to foreign incursions, so in 1826 Busca moved it to Ferrara, then within the Papal States.