Borlase, Sir John (1575/1576–1648), lord justice and army officer, was probably the son of Edmund Borlase, mercer of London, and his wife Suzan, or Suzannah, née Isham. He may have matriculated from King's College, Cambridge in 1591 and he was admitted to the Middle Temple 19 October 1595. He was a soldier in the service of the Dutch United Provinces in the first decade of the seventeenth century, and may have been governor of Portsmouth in 1610. He was knighted, probably in July 1606, and in 1610 he married Alice Ravis, widow of Thomas Ravis, bishop of London. In 1620 he took a command in the English force despatched to Germany to aid Frederick, the Elector Palatine. By 1624 or 1625 he had risen to command an English regiment in Dutch service, transferring to the service of Denmark in 1626. Appointed master of the ordnance in Ireland in June 1634 (with patent dated September), and a privy councillor, he was regarded by Wentworth (qv) as a key figure in Irish military organisation. Though by 1638 Wentworth described him as ‘old and very infirm’ he also referred to him as ‘one whose Judgement I consult much with in all which conduceth to the Government of the Army’ and, indeed, ‘in a manner the only Man we have qualify'd to command in chief under me’ (Knowler, ii, 188, 204). He played a major role in assembling Wentworth's ‘new army’ of 1640.
Elected MP for Enniskillen in 1634 and for Belturbet in 1640, he was appointed lord justice 30 December 1640 and sworn in on 10 February 1641. He was, however, overshadowed by his fellow lord justice, Sir William Parsons (qv), during a term of office that saw the outbreak of insurrection in Ireland and civil war in England. With Parsons's dismissal in March 1643 Borlase was re-appointed lord justice alongside Sir Henry Tichborne (qv); they were sworn in on 12 May and served until January 1644 when the marquis of Ormond (qv) took up office as lord lieutenant. Residing at Chichester House in Dublin during these years, by the summer of 1646 he was in London, where he was joined by other members of the Dublin administration now willing to act in association with the English parliamentarians. Regularly consulted on Irish military issues, he was appointed to the Irish privy council nominated by Westminster in January 1647. He died in London in March 1648, aged 72, being survived by three children, including the historian Edmund Borlase (qv).