Lamberto Grimaldi (c. 1420–March 1494) was a Lord of Monaco (since March 16, 1458). He was married to his cousin Claudine Grimaldi in 1465 in order to secure the Grimaldi inheritance of Monaco which by the small state's constitution could only pass to male heirs. Lamberto was of the branch of the Grimaldi family which had settled in Antibes while Claudia was of the more powerful Monaco branch. Thus their union legitimately kept her branch of the family in control of Monaco. At this period in Monaco's history the family had not yet attained the princely status that was to come later.
Lamberto assumed the reins of power in Monaco at a difficult time in its often vulnerable history. Lamberto fought to preserve Monaco's independence, and is said to have "handled diplomacy and the sword with equal talent".[1] He also established the Grimaldi motto "With God's help."
He and Claudine had at least six children;