Erle, Thomas (c.1650–1720), soldier and lord justice of Ireland, was second-born but first surviving son of Thomas Erle (d. 1650) of Axmouth, Devon, and his wife Susanna, daughter of William Fiennes, 1st Viscount Saye and Sele. He was educated at Trinity College, Oxford (entering on 12 July 1667 aged 17), and at Middle Temple, being admitted on 19 November 1669. He was made a member of King's Inns on 9 June 1702 (following on his becoming a lord justice). He succeeded to the family lands at Charborough, Dorset, on the death of his grandfather, Walter Erle, in 1665.
Prior to commencing a distinguished military career, Erle served in various local county offices before entering national politics in 1679 as MP for Wareham, near Charborough. Although he supported the exclusion of James (qv), duke of York, in 1679–81, when York succeeded to the throne as James II in 1685 Erle demonstrated his loyalty after Monmouth's landing by assuming command of the East Dorset militia (in which he had served as captain since at least 1679), and by fighting as a volunteer at Sedgemoor, for which action he was presented to the king. He was MP for Wareham in 1685–7, but by 1688 had become disillusioned with James II, as a result of which he played a part in the conspiracy to bring William of Orange (qv) over to England, and took a leading role in securing Dorset for William. By that time he was a lieutenant-colonel in the militia, though his activities on behalf of William III resulted in his appointment in early 1689 as colonel of a new regiment of foot in the army, which marked the commencement in earnest of his military career.
Erle commanded his regiment at the battle of the Boyne and the first siege of Limerick in 1690. In January 1691 he was appointed colonel of the older 19th Regiment of Foot. At the battle of Aughrim later that year he was said to have greatly distinguished himself, being twice captured by Jacobite forces, twice rescued by his own men, and severely wounded. With the end of the Irish war Erle's connection with Ireland was severed for a time while he pursued his military career on the Continent, serving at Steinkirk and being wounded at the battle of Landen, when he left his sickbed to partake in the fighting. While continuing to sit as MP for Wareham (1689–98) and Portsmouth (1698–1701) he progressed into the higher ranks of the army, being appointed brigadier-general in 1693, governor of Portsmouth in 1694, and major-general in 1696. Throughout this time he retained the colonelcy of the two regiments of which he had been given command under William III, though the regiment raised in 1689, having lost many men in the failed expedition to Brest in 1694, was disbanded in 1699.
Erle's connection with Ireland was reestablished under the chief governorship of the earl of Rochester (qv). Having been awarded the freedom of Cork in 1700, Erle was appointed in 1701 to the Irish privy council and as commander-in-chief of the land forces in Ireland. After the accession of Queen Anne (March 1702), Erle, who was now in Ireland, was one of three lords justices appointed to supersede the commission of justices in place since Rochester's departure from Ireland at the end of 1701. With his fellow justices, Erle was responsible for assessing the political and financial climate in Ireland in 1702, as it was becoming apparent to the English government that an Irish parliament would have to be convened in the near future, though the outcome of such an event was uncertain given the grievances within protestant Ireland, in particular over the English parliament's resumption of the Irish forfeitures in 1700. In the last months of 1702 the lords justices canvassed the opinion of leading Irish government officials and politicians on these issues. The process culminated in December 1702 with a meeting at Dublin castle, at which Erle promised to do the best he could for Ireland in light of the various grievances being raised by those in attendance, though he was said to have also suggested that it was reasonable that Ireland should bear some of the cost of the war with France. Such a suggestion was believed to reflect a government desire to press an Irish parliament to impose new taxes, which was an unpopular proposal at the best of times.
Erle remained attentive to his military career while in Ireland, and during 1702 pressed Rochester on the question of a further promotion. In February 1703 he was rewarded with the rank of lieutenant-general. At the same time, Rochester was replaced by the 2nd duke of Ormonde (qv) as lord lieutenant. Erle and his fellow lords justices continued in government until Ormonde's arrival in Ireland that summer, while the advice they had previously given for the calling of an Irish parliament was heeded by the new chief governor and the English government. In the ensuing parliament Erle sat as MP for Cork city (1703–13), though he was not overly active in the commons. In February 1704 he was appointed as a lord justice in Ormonde's absence, and received a further mark of favour in June when he was made colonel of a newly raised regiment of dragoons on the Irish establishment. He served as lord justice until Ormonde's return in November 1704, and appears to have been present in the commons for the 1705 session, though thereafter his military career came to the fore once again and his connection with Ireland ended.
In April 1705 Erle left Ireland to take up the post of lieutenant-general of the ordnance in England. On leaving Ireland he ceased to be commander-in-chief of the army and colonel of dragoons. In May he was appointed to the English privy council. He continued to sit as MP for Wareham (1701–18). In 1706 he was made second-in-command of an expeditionary force, and went to Spain with it when the original plan to attack France was dropped. In 1707 he commanded the centre at the battle of Almanza, at which he lost his right hand. The following year he was made commander-in-chief of yet another descent on France, which, although attempted, ultimately failed like previous endeavours, though Erle was not blamed and instead was made commander-in-chief of the land forces in England. In 1711 he was promoted to general of foot. In 1712 he was removed from all offices and, as he had sold his colonelcy of the 19th Regiment in 1709, found himself unemployed for the first time since the revolution. After the Hanoverian succession he was reappointed as lieutenant-general of the ordnance and governor of Portsmouth. In 1718 he was dismissed from both posts and given a pension of £1,200 a year. He died 23 July 1720, leaving as heir his only daughter, Frances, by his marriage (1675) to Elizabeth (d. 1710), second daughter of Sir William Wyndham of Orchard Wyndham, Somerset.