Lucien (1487 – 22 August 1523) became Lord of Monaco on 11 October 1505, having murdered[1][2] his predecessor and brother, Jean II, and held that sovereignty until his death.

According to Françoise de Bernardy's acclaimed history of the Princes of Monaco, it was almost midnight on the evening of October 5, 1505.

[1] In a graphic novel published by Dargaud in 1997, Lucien's explanation to his mother is that he lost his temper when Jean admitted to trying to sell Monaco to the Venetians behind their backs.

[1] A year after Lucien's reign began, Genoa broke free of France, and many of its people fled to Monaco for refuge.

Andrea Doria, the famous admiral and a cousin to Bartholomew, is believed to have had prior knowledge of the assassination.