Sir Francis Drake was the first Englishman to circumnavigate the globe in a famous voyage from 1577 to 1580. He raided Spanish settlements and played a key role in defending England against the Spanish Armada. Sir Walter Raleigh sponsored early English colonies in America but also failed in expeditions to find El Dorado, leading to his imprisonment and eventual execution under King James I. Tudor sailors faced difficult conditions on long voyages in cramped ships with limited food and medical care.