In 1304, at the death of Pope Boniface VIII, he captured Pesaro, Fano, Senigallia and Fossombrone, which he lost and recovered in the following years.
In 1317, he became the lord of Rimini and the head of the Malatesta family at the death of his brother, Malatestino dell'Occhio.
In 1321, he was capitano generale (supreme commander) of the Papal States against the Ghibellines and the Montefeltro of Urbino.
Pandolfo I had two sons: Malatesta II and Galeotto I.
A partition was reached by which Malatesta II succeeded in Pesaro and Ferrantino in Rimini.