George, Third Earl of Cumberland, 1558-1605, His Life and his Voyages

Williamson, George Charles, George, Third Earl of Cumberland, 1558-1605, His Life and his Voyages: A Study from Original Documents, London: Cambridge University Press, 1920.

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Sir George Clifford, 3rd Earl of Cumberland, KG (8 August 1558 – 30 October 1605) was an English peer, as well as a naval commander and courtier in the court of Queen Elizabeth I.
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He is famous for his short lived 1598 capture of Fort San Felipe del Morro, the citadel protecting San Juan, Puerto Rico. He arrived in Puerto Rico on 15 June 1598 but by November of that year Clifford and his men had fled the island due to harsh civilian resistance.