Complex sentence: Hussey was lucky to be adopted by a former ambassador to London, Signor Ghislonzoni, who befriended the painter, who was in Bolgna until 1733, when he left for his original destination of Rome.
Split into simpler sentences: Hussey was lucky to be adopted by a former amabassador to London. Signer Ghislonzoni befriended the painter and he was in Bolgna until 1733 when he left for original destination of Rome.