structural:summarization
Early life

Like many aspects of Cesare Borgia's life, the date of his birth is a subject of dispute. He was born in Subiaco in Lazio, Italy in either 1475 or 1476, the illegitimate son of Cardinal Roderic Llançol i de Borja, usually known as "Rodrigo Borgia", later Pope Alexander VI, and his Italian mistress Vannozza dei Cattanei, about whom information is sparse. The Borgia family originally came from the Kingdom of Valencia, and rose to prominence during the mid-15th century. Cesare's great-uncle Alphonso Borgia (1378–1458), bishop of Valencia, was elected Pope Callixtus III in 1455. Cesare's father, Pope Alexander VI, was the first pope who openly recognized his children born out of wedlock.

Stefano Infessura writes that Cardinal Borgia falsely claimed Cesare to be the legitimate son of another man—Domenico d'Arignano, the nominal husband of Vannozza dei Cattanei. More likely, Pope Sixtus IV granted Cesare a release from the necessity of proving his birth in a papal bull of 1 October 1480.