Henry Cromwell, 1628-74
Son of Oliver Cromwell who as Lord Deputy in Ireland worked to stabilise the Protectorate administration and to reconcile Irish Protestant interests.
The fourth son and fifth of the nine children of Oliver and Elizabeth Cromwell, Henry was born on 29 January 1628 at Huntingdon. He served in Colonel Harrison's cavalry regiment during the civil wars, taking part in the battle of Preston in 1648.
Henry was appointed colonel of a newly-formed regiment of horse late in 1649 and joined his father's army in Ireland in February 1650. He campaigned with Lord Broghill in Munster against Lord Inchiquin, then joined his brother-in-law Henry Ireton at the siege of Limerick in 1651.
Henry returned to England early in 1653 and married Elizabeth Russell (1637-87), daughter of Sir Francis Russell. They had seven children; their great-grandson, who died in 1821, was the Protector's last direct male descendant.

During the spring of 1653, Henry was named as one of the representatives for Ireland in the Nominated Assembly, where he was an active member of the moderate faction. After the establishment of the Protectorate, Henry was sent back to Ireland in March 1654 to report on the political and religious allegiances of army officers, and to investigate their attitudes towards Oliver Cromwell's assumption of power. He was deeply critical of the republican Edmund Ludlow and recommended his dismissal. He also criticised Charles Fleetwood for his encouragement of Baptists and other radical religious sects. On returning to England, he was elected MP for Cambridge University in the First Protectorate Parliament.
In July 1655, Henry returned to Ireland and took over from Fleetwood as chief administrator. Fleetwood's administration was regarded as unsatisfactory and he was invited to return to England, but he was not required to resign as lord deputy until his three-year commission had expired in September 1657. Henry was expected to consult with Fleetwood before making major decisions, which hampered his work and soured his relationship with Fleetwood. Henry was finally appointed lord deputy of Ireland in November 1657.
Henry's principal objective in Ireland was to secure the authority of the Protectorate and to crush all disloyalty. He opposed the Baptists among the soldiers and civilian administrators because of their close association with republicans.

By late 1656, Henry had succeeded in forcing leading Baptist officers to resign their commissions or to leave Ireland. He discouraged the spread of Quakerism into Ireland by arresting Quaker missionaries and dismissing army officers who appeared susceptible to their message. On the other hand, he encouraged moderate Presbyterian and Independent clergymen to come over to Ireland. Having suppressed the radicals, Henry worked to reconcile the main Protestant groupings, to gain the support of the gentry and to stabilise the administration. The policy of land seizure and transplanting the native Irish was largely carried out before his appointment as lord deputy, so although he remained suspicious and watchful, Henry's treatment of the Irish Catholics tended to be moderate.
Henry supported the succession of his brother Richard Cromwell to the office of lord protector in 1658. However, he was disappointed not to be invited to England to confer with him. Henry was elevated to the office of lord lieutenant of Ireland in November 1658 but was powerless to prevent the collapse of the Protectorate the following year. The re-instated Rump Parliament passed a resoution that Ireland should be governed by commissioners rather than by a single person and Henry resigned as lord lieutenant in June 1659.
Henry was treated generously at the Restoration and allowed to keep most of his Irish lands. Eventually he retired to Spinney Abbey in Cambridgeshire, where he died in 1674.
Sources:
Maurice Ashley, Cromwell's Generals (London1954)
C.H. Firth, The Last Years of the Protectorate 1656-58 vol. ii (London 1909)
Peter Gaunt, Henry Cromwell, Oxford DNB, 2004