Robert Devereux, 2nd Earl of Essex (1566-1601), was an English nobleman and military leader during the late 16th century. He was the son of the 1st Earl of Essex and became a prominent figure in the court of Queen Elizabeth I. Devereux was known for his charm and ambition, which helped him gain favor with the queen, leading to various military appointments. Despite his early successes, Devereux's fortunes declined due to political conflicts and his growing rivalry with other courtiers. His failed military expedition to Ireland in 1599 led to his downfall, and he was ultimately executed for treason in 1601.