House of Grimaldi
Grimaldi was born on 17 December 1736 into the noble House of Grimaldi of Monaco as lord of Cagnes and Antibes, in the château of Cagnes, in southeastern France. He was the son of Honoré IV Grimaldi, Marquis de Cagnes and Hélène-de-Orcel Plaisians, and belonged to the ancient nobility of France, descended from the House of Bourbon.