He was the eldest son of Sir Edward Unton of Wadley House at Faringdon in Berkshire (now Oxfordshire) and Anne, the daughter of Edward Seymour, 1st Duke of Somerset and widow of John Dudley, 2nd Earl of Warwick.
His brother Henry paid a ransom of 10,000 crowns to secure his return to England, where Edward was obliged to sell part of his inheritance to repay his brother.
In 1587 he went as a colonist to Munster but was recalled due to the imminent threat of the Spanish Armada.
Afterwards he went as a captain on the Portuguese expedition (the English Armada) led by Sir John Norreys, but returned in bad health to die in 1589.
His widow married Sir Walter Chetwynd of Ingestre in Staffordshire.