In 1715, Jacques Goyon de Matignon married Louise Hippolyte, Princess of Monaco, the last Grimaldi agnatic heir.

Rainier III, son of Pierre de Polignac, inherited the title through Princess Charlotte, Duchess of Valentinois in 1949 and adopted the Grimaldi name.

The Grimaldis feared that the head of a rival Genoese family could break the fragile balance of power in a coup and become lord of Genoa, as had happened in other Italian cities.

During this period, both the Guelphs and Ghibellines took and abandoned the castle of Monaco, which was ideally located to launch political and military operations against Genoa.

The House of Grimaldi provided several doges, cardinals, cabinet ministers, and military officers of historical note.

Provence became a part of the Kingdom of France from 1486, and occasionally the Grimaldi relied upon French support to preserve their independence from the Republic of Genoa and the Duchy of Savoy.

[citation needed] Under the succession rules prior to 1911, Monaco's throne would have passed to Prince Wilhelm of Urach.

However, French president at the time Raymond Poincaré had threatened that if the throne was inherited by a German, France would annex the principality.

Article I of Monaco's house law requires that the reigning Prince or Princess bear the surname of Grimaldi.

The coat of arms of the House of Grimaldi is simply described as fusily argent and gules, i.e., a red and white diamond pattern, with no further modifiers.