Tommaso II Sanseverino was born around 1255 to Ruggero II Sanseverino and Theodora d'Aquino. He became count of Marsico, baron of Cilento, Diano, Magliano Vetere, Sanseverino and Sant'Angelo a Fasanella. Over the years there were also successive governments in the territories of Atena, Camerota, Centola, Monteforte, Padula, Polla, Sanza and Serre. He was greatly influenced by his uncle, Saint Thomas Aquinas, who had stayed at the castle of Arechi, where he had one of his ecstasies: in fact, he took an active interest in the glorification of his uncle. In 1284 Charles II of Anjou entrusted Ruggero II to his father the custody and defense of Salerno from the rebels, while he appointed Thomas II captain, sending him to defend the coast that goes from Salerno to Policastro. He died on the 25th of September 1324, at the age of approximately 72, being buried in the chapel of the Padula charterhouse.

Tommaso II Sanseverino is known for having had the Certosa di Padula (also called Certosa di San Lorenzo) built in 1306, whose works of construction began on January 28th.