Born the son of Jerome Wade in Killavally, Westmeath in Ireland, Wade was commissioned into the Earl of Bath's Regiment on 26 December 1690 and served in Flanders in 1692, fighting at the Battle of Steenkerque in August 1692 during the Nine Years' War and earning a promotion to lieutenant on 10 February 1693. He transferred to Sir Bevil Granville's Regiment on 19 April 1694 and was promoted to captain on 13 June 1695.
During the War of the Spanish Succession he first served under Marlborough, seeing action in Flanders at the Battle of Kaiserwerth in April 1702, the Battle of Venlo in September 1702, the Battle of Roermond in October 1702 and Battle of Liège also in October 1702. He was promoted to major on 20 March 1703 and to lieutenant colonel in October 1703. In 1704 he joined the staff of Henri de Massue, Earl of Galway as adjutant-general in Portugal, and distinguished himself as colonel of the Huntingdon's Regiment during the Battle of Alcántara during which he was wounded in April 1706. He repelled a large force of cavalry at Vila Nova and then commanded the 3rd infantry brigade during the Battle of Almansa in April 1707. He won promotion to brigadier general on 1 January 1708.
He served as second-in-command to James Stanhope in Menorca in 1708, leading one of the storming parties on Fort St. Philip, before returning to Spain in 1710, where he fought at the Battle of Saragossa in August 1710. He was promoted to major-general on 3 October 1714 and became commander of the British forces in Ireland in November 1714.
Wade returned home to join in the suppression of the Jacobite rising of 1715 and undertook security duties in Bath, where he unearthed a haul of Jacobite weapons. He entered politics as MP for Hindon in 1715. On 19 March 1717 he became colonel of the Earl of Plymouth's Regiment of Horse.
In 1719 he served as second in command to Viscount Cobham during the War of the Quadruple Alliance when Cobham led a force of 4,000 troops on a raid on the Spanish coastline which captured Vigo and occupied it for ten days before withdrawing.