Ley, James (c.1552–1629), 1st earl of Marlborough, judge , was baptised at Barford, Wiltshire, the fourth son of Henry Ley of Teffont Evias, Wiltshire, and Dyonsia Seymour. After graduating BA from Brasenose College, Oxford, on 3 February 1574, he was admitted to Lincoln's Inn on 18 February 1577, and was called to the bar in 1584. He sat as MP for Westbury in 1597–8, 1604–5, 1609–11, and 1620–21, and for Bath in 1614. In 1603 he became second justice for the Carmarthen circuit and was knighted on 9 December the same year. That winter he went to Ireland, having being made chief justice of the court of king's bench there on 16 December 1603.
This was a crucial period in Irish legal history, as for the first time the common law could be applied throughout the island. He frequently rode the judicial circuit in Leinster and Ulster, going to areas which had rarely or never before seen a common law assize. The government suffered at this time from a shortage of qualified and reliable judges, because of the gradual exclusion of catholics from judicial office, making Ley's talents all the more appreciated. While in Ireland, he played a key role in the revival of King's Inns on 18 June 1607, becoming a member of the society on that day. His interest in this project stemmed from his exalted regard for the legal profession and ensuing concern to establish and maintain strict professional standards within it.
In December 1605 he became the focus of controversy following the government's decision to initiate its ‘mandate’ policy, which involved fining influential members of the Pale community who refused to attend protestant church services. Because he was responsible for its implementation, it was widely held to be his idea. Most likely the prime mover was the lord deputy, Arthur Chichester (qv), but the recusants, perhaps realising that the king would never dismiss his chief governor, called for Ley's head instead. Chichester and the other members of the Irish administration backed him to the hilt, praising his abilities in the strongest terms. Nonetheless they were clearly worried, and in April 1606 Chichester prepared to send Ley to London to defend himself. However, on 3 July the English government wrote to affirm its confidence in him and declared that his going to London would be interpreted as a sign of weakness.
In January 1608 he was made commissioner for the proposed plantation of Ulster and in October he travelled to London to brief the English government on it. On meeting him, the king was so impressed that in December he made him attorney of the court of wards in England, bringing his Irish career to an end. After being created a baronet on 20 July 1619, he was chief justice of the court of king's bench (1621–4), speaker of the house of commons (May–July 1621), lord high treasurer (December 1624 – July 1628) and president of the privy council (July–December 1628). He was sworn a member of the English privy council on 20 December 1624 and was created earl of Marlborough on 5 February 1626. Although undoubtedly one of the brightest legal minds of his time, his rise was due primarily to the power of his close relative the duke of Buckingham. Indeed, he had clearly been promoted beyond his abilities as treasurer, and was eventually obliged to resign in July 1628.
After 1608 he continued to exercise considerable influence over Irish affairs, being involved in the preparation for the plantation of Ulster. He was appointed to the newly instituted commission for Irish affairs (1611), and again upon its re-establishment in 1623. In 1624, he was appointed to the committee for Irish affairs. As lord treasurer he was heavily involved in the negotiation of the Graces (1626–8). While he was in Ireland he had collected, with a view to publication, three early Irish chronicles: ‘The annals of John Clynne’, ‘The annals of the priory of St John the Evangelist’ and ‘The annals of Multifernan, Ross and Clonmel’. He had also helped to instigate the printing of the first copy of the Book of Common Prayer in Irish and wrote a number of legal treatises, which were published after his death.
He died at Lincoln's Inn, London, on 14 March 1629. Ley married first Mary, daughter of John Petty of Stoke Talmage, Oxfordshire; second another Mary, widow of Sir William Bowyer; and third Jane, daughter of John, Lord Boteler, and of the duke of Buckingham's sister. With his first wife Ley had two sons and eight daughters. His portrait still hangs over the door to the council room in the upper vestibule at Lincoln's Inn.