Robert Devereux, 1st Earl of Essex (1566-1601), was an English nobleman and military leader during the late 16th century. He was the son of Walter Devereux, 1st Viscount Hereford, 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. Despite his early successes, including military campaigns in Ireland, Devereux's fortunes declined due to political conflicts and his attempts to gain more power. In 1601, he led a failed rebellion against the queen, resulting in his execution for treason.