Before dying in 1458, Alfonso granted the status of nobility to Galceran and to his brother Bernat de Requesens y de Santa Coloma, but the "Biga" group they represented disputed John II's succession to his brother Alfonso, claiming new and old laws implemented along the Catalan counties' history.
The "Biga" had supported the unfortunate Prince Charles of Viana, half-brother of the later king Ferdinand II, as a candidate to inherit the Navarrese throne.
The defeat in 1461 of Charles, fighting against his father John, legal king of Aragon since 1458 on the death of his brother Alfonso V, led to the so-called capitulation of Vilafranca del Penedès and Charles's imprisonment by John, as well as to his premature death under suspicious circumstances.
Galceran and his wife Elisabeta Joan de Soler, from Valencia, had 13 children, many of them entrepreneurs, international merchants and members of the Aragonese nobility settled there.
Galceran de Requesens was eventually made destitute and went to prison for 108 days before being exiled to Valencia, where he died in 1465.