Galeazzo II Visconti was the son of Stefano Visconti and Valentina Doria. The House of Visconti held family ties to Pisa, Sardinia and Milan. Originally, the founding of the Milanese Visconti line was a particularly contested issue. Galeazzo's ancestors, Azzone and Ottone Visconti both held legitimate claims to be considered the founder of their house. However, it was under Ottone that the power of the Visconti house expanded before becoming the dynastic power they were later infamous for. Previously, the Visconti family had only enjoyed limited privileges within the city. As a result of his efforts, Ottone was recognized as the official founder of the Visconti house over Azzone.