Warren, Nathaniel (c.1737–1796), merchant, MP, and first commissioner of police, was born in Dublin. His parentage is unclear, but a number of Warrens were engaged as merchants and glaziers in the city prior to his birth. Alternatively, he may be the son of Oliver Warren, naval officer, who resided at Warrenstown, Co. Meath. Some sources suggest that Nathaniel Warren was a brewer, but he was styled as ‘merchant’ throughout his career and not listed among brewers in Dublin trade directories. He seems to have traded from various premises along William St., Dublin, from the 1760s until his death, but also lived in Aungier St., Crampton Court, Mill St., Nealstown House, and Stillorgan. He was a merchant of some standing; by the 1770s his personal estate was worth at least £2,000 and he held lands in Stillorgan, Kilmacud, Nealstown, and Springfield, Co. Dublin, which yielded a rental of about £500 a year in the 1790s. Through his marriage (c.1770) to Catherine Higgins he acquired properties on Anne St. and Dawson St., Dublin. In 1765 he was admitted into the Dublin civic franchise and granted freedom of the city. He served as a sheriff for the city of Dublin 1773–4 (having been unsuccessfully nominated the previous year), was made an alderman for life in June 1775, was senior master of the Trinity Guild in 1776, and served as lord mayor of Dublin 1782–3.
During the 1770s and 1780s Warren was one of the more active aldermen in Dublin and was instrumental in pushing for improvements such as paving, lighting, and cleaning the city's streets, and sat on numerous boards and commissions. The Dublin assembly roll of 1783 records a vote of thanks for ‘his indefatigable assiduity to the duties of that office [as chief magistrate] and his strenuous endeavours to promote its trade and support its manufactures’ (Calendar of ancient records of Dublin, xiii, 327). In the following year he was also thanked for the ‘the very accurate and clear’ manner in which the city council's annual accounts were presented. His civic duties also extended to other areas; he sat as a governor for the Blue Coat Hospital school, the Foundling Hospital, the Lying-in Hospital, and the Hibernian Fire Insurance Company. He served as a captain in the Dublin regiment of Volunteers in 1778 and attended the national volunteer convention on behalf of the city of Dublin in 1783.
He was elected unopposed as MP for Dublin city at a by-election in 1784 (having been defeated at his first attempt to enter parliament in 1782) and served until 1790. Warren was the first alderman to represent the city since the 1760 corporation act, and seems to have been elected on the basis of his civic record rather than his political views. He was neither a radical (with an agenda to challenge the British parliament) nor a supporter of Dublin Castle. In 1786 he was appointed as one of three commissioners of police in the city of Dublin. The Dublin police act of 1786 led to the establishment of a force of constables directed by chief constables and commissioners in the city of Dublin. Warren played a pivotal role in this new police service and petitioned the government to create hundreds of additional constables, to build more houses of correction, and to pay the officers proper salaries. He did not, however, advocate prison reform and was against the introduction of new prison officials. Though most ratepayers approved of the new measures to tackle crime, they were not prepared to pay additional taxes to support them. Furthermore, some freeholders felt that the new police force was a threat to their liberty and a means of strengthening the aldermanic interest. Warren advocated, for example, that the chief constables should be authorised to carry out summary corporal punishment. In 1789 he became the first (or ‘chief’) commissioner of police. Intense anti-police feeling meant that he was forced to withdraw from standing again as MP for the city of Dublin at the general election in 1790. Instead he represented the borough of Callan, Co. Kilkenny, until his death. Callan was a ‘rotten borough’ under the control of the Agar family and in the government's interest. In 1789 Warren voted against the regency bill and in the following year voted for John Foster (qv) as speaker of the house of commons.
Warren was an able and conscientious officeholder in the city of Dublin, and in the four years before his death he was appointed an auditor of the city accounts, superintendent magistrate, and commissioner of array for the Dublin militia. His role in the creation of an embryonic professional police force in Dublin – one of the first such forces in Europe – was especially significant. He did not, however, appreciate the importance of creating a more efficient and less corrupt prison system in tandem with a new police force. From 1786 the police commissioners inspected Dublin's overcrowded prisons but did not request any significant improvements. Warren advocated corporal punishment rather than incarceration. He died on 15 January 1796 in Dublin, aged about 59, and his estate was divided up equally between his three daughters. His only son, James Taylor Warren, died in Bombay in 1799.