Born into a Roman Catholic family in London, Gage was educated abroad and spent three years at the English College in Rome. Having no desire to become a priest, he enlisted in the Spanish army of Flanders in 1620. He served under the Spanish general Ambrosio Spinola at the siege of Breda, which surrendered after a 10-month siege in 1625. Gage returned to England in 1626 when King Charles I declared war on Spain. In 1627, he published his translation of Herman Hugo's Latin account of the siege of Breda. Some time later, he married Mary Daniel. When peace was signed with Spain in 1630, Gage returned to Flanders. He commanded an English regiment in the Spanish service from 1631-43, distinguishing himself in July 1638 when he successfully defended St Omer against the French.
When the Bishops' Wars broke out between England and Scotland in 1639, Gage attempted to broker a loan from the Spanish government for King Charles. He secured weapons for the Royalists on the outbreak of the English Civil War and returned to England to fight for the King in 1644, leaving his family in Flanders. With his extensive military experience, Gage was appointed to the King's Council of War, arousing the jealousy of the governor of Oxford, Sir Arthur Aston. On 12 June 1644, Gage led a force from Oxford on a successful expedition to recapture Boarstall House near Aylesbury. His most famous exploit was the relief of Basing House in September 1644 when he broke through Parliamentarian lines to bring provisions to the beleaguered garrison then skillfully led his entire force back to Oxford. Gage also accompanied the Earl of Northampton to the relief of Banbury Castle in October 1644.
Gage was knighted for his services to the Royalist cause in November 1644. On Christmas Day, he was appointed governor of Oxford after Sir Arthur Aston was incapacitated in a riding accident. The appointment was generally popular, but proved to be brief. Gage was mortally wounded at a skirmish on 11 January 1645 while leading an attempt to secure Culham Bridge on the outskirts of Oxford. He was buried in Christ Church Cathedral, Oxford, with many senior officers and courtiers attending his funeral.
Reference:
A. J. Loomie, Henry Gage, Oxford DNB, 2004