In his will, he stated that he was to be succeeded by his daughter Claudine who (to adjust to the will of his father that a female ruler was not to result in a change in dynasty), was to marry her seventh cousin Lamberto Grimaldi di Antibes, to ensure that the Grimaldi family should keep the throne of Monaco and avoid a change in dynasty.

[1] In July 1457, Catalan died when Claudine was at the age of six, and her paternal grandmother Pomellina Fregoso duly became regent of Monaco in accordance with the written will of her son.

[1] On 20 October therefore, Pomellina saw herself forced to sign a statement in which she was to share the power of regency with Lambert.

[1] In March 1458, the plot was staged, but Lambert managed to escape: with the support of the population of Menton and Roquebrune, he deposed Pomellina's regency government, confined her to her house in Menton, and had himself declared sovereign Lord as well as the regent and possessor of the rights of Claudine.

[1] The dynastic marriage between Claudine and Lambert was regardless to take place, but was postponed because of the young age of the bride.

She also reinstated her granddaughter Marie Grimaldi (daughter of Jean II) in the succession, despite Lucien having forced her to renounce her claims upon her marriage.