[2][3][4] In 1209, both William IV and Alfonso died and Garsenda became the natural guardian of their son and heir, Raymond Berengar V. Initially her brother-in-law, Peter II of Aragon, assigned the regency of Provence to his brother Sancho, but when Peter died in 1213 Sancho became regent of Aragon and passed Provence and Forcalquier to his son Nuño Sánchez.

The Provençal aristocracy originally took advantage of the situation for their own ambitious ends, but eventually they lined up behind Garsenda and removed Nuño, who returned to Catalonia.

In 1220, Guillaume II de Sabran, a nephew of William IV, who claimed Forcalquier and had been in revolt in the region of Sisteron, was neutralised in part through the mediation of the Archbishop of Aix, Bermond le Cornu.

As the father of infant Beatrice, Henry III of England, was engaged in a war in France at the time, she brought sixty knights to his service.

[8] Garsenda may have been alive as late as 1257, when a certain woman of that name made a donation to a church of St-Jean on the condition that three priests be kept to pray for her soul and that of her husband.