George Townshend, 4th Viscount and 1st Marquis Townshend, was born February 28, 1724, the eldest son of Charles, 3rd Viscount (1700-1764), and his wife Etheldreda Audrey Harrison (ca. 1708-1788). In 1741, his parents formally separated, and, unlike his younger brother Charles Townshend (1725-1767), future chancellor of the exchequer, he sided with his mother, who was known for her wit and sympathy for the Jacobites. In 1743, during a tour of Europe, he enlisted in the British army in Flanders as a volunteer, and in 1745, was appointed captain in the 7th (Cope's) Regiment of Dragoons. In 1746, he served under the Duke of Cumberland at the Battle of Culloden, and the next year became his aide-de-camp, and eventually reached the position of lieutenant-colonel. In 1749, he graduated from St. John's College, Cambridge. Around this time, he fell out with the Duke of Cumberland, and took an eight year absence from the military in 1750.
Around this time, Townshend became increasingly involved in politics, standing for Norfolk in 1747 while still in Flanders, and later in the decade strongly supporting a bill that called for the extension of the British militia in lieu of a standing army. He also gained prominence as a caricaturist, but his skewering of politicians gained him many enemies. During the Seven Years War, he returned to the British army and served as a brigadier in Quebec under Major-General James Wolfe, whom he disliked and caricatured. Upon the death of Wolfe and wounding of Robert Monckton, Townshend, as Wolfe's second-in-command, assumed command of the British forces in the Siege of Quebec and accepted the surrender of the city on September 18, 1759. He was promoted to the rank of major-general in 1761, and fought at the Battle of Villinghausen in July of that year.
After his return to England, Townshend served as lieutenant general of the ordnance from 1763 to 1767, and through the influence of his brother Charles, who was chancellor of the exchequer, he was named lord lieutenant of Ireland in 1767. In an attempt to rebuild the Crown's influence in Irish politics, Townshend was ordered to take up residence in Dublin. His first major task was to augment the size of the British army in Ireland in order to equalize the regiment size between British and Irish units, an unpopular measure among Irish politicians. He was also directed to break the political power of the unruly "Undertakers" of Irish Parliament. He succeeded, but only by using methods so corrupt that he was recalled in 1772. Townshend returned to his ordnance post and did not hold another important public office, though he lived until September 14, 1807.
On December 19, 1751, Townshend married Charlotte Compton, 15th Baroness Ferrers of Chartley, with whom he had eight children. After her death on September 3, 1770, he married Anne Montgomery in 1773, and with her had six children.