Waterhouse (Waterhous), Sir Edward (1535–91), chancellor of the Irish exchequer, was born at Helmstedbury, Hertfordshire, youngest son of John Waterhouse of Whitechurch, Buckinghamshire, and his wife Margaret, daughter of Henry Turner of Blunt's Hall, Suffolk. Having commenced his studies at Oxford around 1547, he became (c.1548–9) a personal servant of Princess Elizabeth (from 1558 Queen Elizabeth I), serving as such for sixteen years. During this time he became an adherent of Sir Henry Sidney (qv), and when Sidney came to Ireland as lord deputy in 1565 Waterhouse accompanied him as his private secretary. Within days of Sidney formally beginning his duties, he granted Waterhouse a lease of the manor of Monasterevan, Co. Kildare, and appointed him clerk of the court of castle chamber (1 February 1566), in which he served until October 1569. Despite his not holding a great office of state, his industry and closeness to Sidney made him an influential figure. Sidney often sent him to London to gain support for his policies. In 1570 he helped the town of Carrickfergus get a charter of incorporation, granted on 20 March, in gratitude for which he was made a freeman and elected MP for the town in 1585.
He left Ireland in 1570, but he returned three years later to assist Walter Devereux (qv), 1st earl of Essex, who was attempting to colonise parts of east Ulster. Waterhouse subscribed to this scheme, raising ten horse for Essex's army in return for land in Ulster. He accompanied Essex and his men to Carrickfergus in autumn 1573, but from summer 1574 was based mainly in Dublin, where he oversaw the provisioning of Essex's army. In this role he attracted controversy, being accused of corruption in 1575. As his trusted confidant, Waterhouse regularly represented Essex at court during 1573–6. However, the venture failed, and Essex died in Dublin on 22 September 1576 with Waterhouse present. Later, he wrote a widely read account of Essex's last days.
By then, Sidney had been reappointed lord deputy of Ireland and Waterhouse became his secretary once more. On 25 June 1576 he was granted a pension of ten shillings sterling a day, which on 26 June 1579 was granted to him for life. As before, he represented Sidney on sensitive missions to London. From summer 1577 he spent most of the next year in London on Sidney's behalf, vainly attempting to counter the complaints of envoys from the Pale against the exactions of the royal army. Despite Sidney's humiliating dismissal from office in 1578, Waterhouse returned to Ireland and resumed working as secretary to various governors and on various government commissions. Thereafter, he quickly amassed a multiplicity of government positions, becoming customer of wines in Ireland's ports (5 February 1579), exchequer commissioner of the army (27 June 1579), receiver of all casual profit of the crown (25 July 1579), and water bailiff of the River Shannon (17 June 1580). He also received a twenty-one-year lease on lands at Hilton, Co. Meath, on 22 July 1581 and was granted the castle and manor of Doonass, Co. Clare, on 26 August 1581.
He spent most of late 1579 and early 1580 in Munster, where the second Desmond rebellion had erupted. He played a major role in organising the government's war effort and, with reluctance, agreed to assume joint responsibility for provisioning the royal army. In recognition of his pivotal role in the administration, he was sworn a member of the Irish privy council in October 1579. His advance was furthered by his close relationship with Sir Francis Walsingham (secretary of state 1573–90), to whom he wrote frequent reports on Irish matters. Like Walsingham, Waterhouse was a zealous protestant and feared catholic conspiracies against the English crown. He was part of an influential group of English-born protestants on the Irish council who distrusted the traditionally loyal Old English catholics and believed that harsh measures were required to bring order to Ireland. During 1580–81 Waterhouse and his cohorts persuaded the lord deputy, Arthur Grey (qv), to adopt a hard line towards the Munster rebels and towards those implicated in the Pale-based Baltinglass revolt of summer 1580. In 1581 Waterhouse was commissioner for attainted lands in Co. Kildare following the suppression of the Baltinglass rebellion, but was disappointed in his expectation of being granted some of this land; Grey distributed the confiscated property among his own cronies.
This soon became the least of Waterhouse's concerns. Appalled at the financial cost of their policies, at the start of 1582 Elizabeth turned on Walsingham and his Irish clients, questioning their management of her finances in Ireland. Waterhouse's plurality of offices made him an obvious scapegoat, and his former allies on the Irish privy council accused him of corruption. Particularly controversial was his post as water bailiff of the Shannon, which had been granted to him and his heirs forever. This post gave him an annual fee of £400, which was to be spent on two boats and their crews to supply the royal forces and to root out pirates. The generosity of his salary is indicated by the fact that his successor enjoyed a mere £40 a year. Moreover, he was accused of not properly maintaining the boats and of simply pocketing most of the fee. It later emerged that he had leased islands on the Shannon for his own benefit and levied a private tax on property owners along the river's bank.
The queen summoned him to London, where in early December 1582 he met Lord Burghley, whom he placated by promising to surrender his office of water bailiff. Nonetheless, even after his return to Ireland in April 1583, he remained under a cloud and the queen ordered that a list be drawn up of all the offices and perquisites he had accumulated since 1576. In March 1584, he participated in the torture of Dermot O'Hurley (qv), Roman catholic archbishop of Cashel, who was martyred at Dublin on 20 June. The same day Waterhouse was knighted by Sir John Perrot (qv), newly appointed lord deputy, at Christ Church cathedral. The queen queried this honour, but Perrot stated that Waterhouse merited it because he spent over 1,000 marks (£666. 13s. 4d.) a year in performing his duties. This was probably true, but the queen suspected that he was earning far more.
Despite Perrot's support, during 1584–5 Waterhouse was obliged to resign his posts as secretary to the lord deputy and as receiver of the casual revenues. Humiliatingly, the queen revoked his patent as water bailiff of the Shannon. In 1586 he went to London to petition for restoration to this post, armed with detailed accounts of his years of service. His critics claimed that he had received fees well in excess of £1,000 each year from myriad government posts. He riposted that he normally received only a fraction of his official salary and had been forced to sell lands in England worth £4,000 in order to maintain himself in Ireland. This mission was a success, and he was made chancellor of the exchequer in Ireland on 19 October 1586 and restored to his post as water bailiff on 7 July 1588, albeit only for his life.
He was close to Perrot, who proved a controversial lord deputy, but Waterhouse defended him from his critics. In particular, he supported Perrot's efforts to extend the crown's power into Ulster, accompanying him on campaigns into the province. His interest in Ulster probably stemmed from the fact that Robert Devereux (qv), 2nd earl of Essex and heir to Waterhouse's old patron, held royal title to land in Monaghan. In 1586–7 Waterhouse proposed a scheme whereby Essex and Hugh O'Neill (qv), 2nd earl of Tyrone, would largely control Ulster on behalf of the crown. The implementation of this scheme could have averted the disasters of the 1590s, but it foundered partly due to Essex's lack of interest in Ireland.
In autumn 1589 Waterhouse was a commissioner in Munster for settling land disputes arising from the plantation there. By then, Perrot had been succeeded as lord deputy by Sir William Fitzwilliam (qv), with whom Waterhouse had an uneasy relationship. He resigned as chancellor of the exchequer in October 1589 and left for England, intending to retire to his estate at Woodchurch, Kent. After reluctantly returning to Dublin in spring 1590, he left Ireland for good that summer and died 13 October 1591 at Woodchurch.
Waterhouse married first Elizabeth, daughter of George Villiers, whom he divorced in 1578. He then married Margaret Spilman, of Kent, and finally Deborah Harlackenden of Whitechurch, a widow, who survived him. The dates of his marriages are unknown; he had no children.