Giovanni Battista was an enslaved baptized Muslim from Tunisia, originally named Ali, who who was manumitted in Pisa in 1529. He was still active in Pisa 30 years later when he requested an authenticated copy of his manumission contract.
Aly de Tunisi... vocatum Iohannem Baptistam... pili olivigni... sclavum
Spedale Trovatelli, item dated 1529-02-20
Spedale Trovatelli, item dated 1559-08-30