He soon became the terror of Muslims on the waters and shores of the Mediterranean, continually raiding along the Barbary Coast, the Levant and the Aegean Sea and capturing numerous ships and slaves.
A hole was punched into its bottom and from it emerged Romegas, with his pet monkey, having somehow managed to stand for hours up to his chest in water in an air bubble under the keel of the ship.
Serving with the Order’s General of the Galleys, Gozon de Melac, Romegas battled repeatedly with the galleys of Turgut Reis, captured Penon de Velez in 1564, on the North African coast opposite Malaga, a major stronghold of the Barbary Pirates, and enraged the Ottoman emperor Suleiman.
During the siege itself, Romegas played a prominent part, leading several thousand knights and soldiers in the defense of the Great Harbor.
When the siege ended, he immediately returned to raiding Muslim shipping, continuing to build his reputation as a fearless warrior and defender of Christendom.
With his record of valor and success, he seemed destined to be elected Grand Master in due course, but he was eventually tripped up by the intrigues and machinations of several senior members of the Order who sought to use his prestige and influence for their own ends.
In 1581, this led to a virtual mutiny, when the General Convent deposed La Cassiere and placed him in confinement in Fort St. Angelo, making Romegas the de facto Grand Master.