William Lee Rees was born probably on 16 December 1836 at Bristol, England, the son of James Rees, a surgeon, and his wife, Elizabeth Pocock. Rees's father died when he was young, and he was brought up by his mother and his uncle. He was educated by a private tutor.
Rees emigrated to Melbourne, Australia, around 1851, presumably with his mother. He began studying law at the University of Melbourne but soon became more interested in religion, and trained as a Congregational minister. He was ordained in 1861 and served as minister to the parish of Beechworth for four years. The law, however, provided a much better living, and after being admitted to the Bar in 1865, Rees practised as a barrister and solicitor. He married Hannah Elizabeth Staite (known as Annie) in Melbourne on 8 July 1863; they were to have seven children.
The goldrush drew Rees to Otago, New Zealand, in 1866. He worked briefly in Dunedin and was admitted as a barrister and solicitor of the Supreme Court in 1866. He then spent three years at Hokitika before moving to Auckland, where he practised law.
Rees became interested in politics in the early 1870s as a supporter of George Grey. He supported Grey's defence of the provincial system and joined in criticising Julius Vogel's borrowing programme. Rees also argued in a pamphlet, The coming crisis (1874), that New Zealand needed a strong central government free of the dominance of Otago and Canterbury. He served on the Auckland Provincial Council as member for Auckland East from 1875 to 1876, and was MHR for City of Auckland East from 1876 to 1879.
Rees's views on Māori land policy were close to those of Grey. He argued that Crown pre-emption should be reintroduced to open up the North Island for closer settlement. Only the Crown could ensure that fair deals were secured with Māori sellers and that land would be sold to small bona fide sellers rather than monopolists and land sharks.
Grey became premier in 1877 and offered Rees the post of attorney general; Rees deferred to the more politically experienced Robert Stout. He then determined to find a solution to the tangled land problem on the East Coast. In 1878 he took over the Napier legal practice of John Sheehan, Grey's native minister. He then carried the Repudiation movement from Hawke's Bay to Poverty Bay by shifting to Gisborne and serving as counsel to Ngāti Porou in their claims against the questionable land purchases of Captain George Read. Rees enjoyed assuming the high moral ground in condemning the transgressions of land monopolists. His legal advocacy and strong rhetorical outbursts won him the firm alliance of Māori leaders such as Wī Pere of Rongowhakaata and Te Aitanga-a-Māhaki.
Rees and Wī Pere formed a company to side-step the litigation caused by the complex native land laws and make more Māori land available for settlement. As a way of ensuring that Māori owners received a fair price and that sufficient land was left to ensure the survival of Māori farming, Rees persuaded owners to allow himself and Wī Pere to act as trustees with absolute power to deal with lands as they saw fit, provided that they worked in constant communication with committees elected to represent the owners. Rees insisted that he could make no personal gain from such an arrangement. He did live in considerable comfort, but was not as obviously wealthy as some of his political opponents; in 1882 he owned only 750 acres in Napier, and at his death he left assets valued at less than £100. Whatever the validity of claims of ulterior motives made by his enemies, Rees's informal trust scheme failed to put an end to litigation or to find a way of investing sale moneys in the development of remaining Māori land.
The more elaborate New Zealand Native Land Settlement Company Bill was introduced in 1883 to open up a quarter of a million acres and so satisfy the considerable investment of Auckland capitalists (which amounted to more than £100,000). This bill also failed, because of fear of local monopoly and because conservative politicians were wary of the machinations of Grey's supporters, especially in Māori land dealings. Rees was soundly beaten when, in 1884, he ran for the East Coast seat.
Rees continued to promote his scheme but the Stout–Vogel government of 1884–87 proved no more sympathetic. An attempt by Wī Pere and Rees to promote their scheme in Britain in 1888 failed when Premier Harry Atkinson declared that the title to the land was insecure. Some £100,000 of investors' money was lost when the company failed, and much Māori land was left in an uncertain legal position. Serious doubts were cast on Rees's integrity and competence, but his name was partially cleared by a committee of inquiry in 1891. The passing of the Mangatu No 1 Empowering Act 1893 established a committee to manage 100,000 acres as a trust. Significantly, Wī Pere played a major part in the new trust but Rees's name was absent. The company now held liabilities worth over £241,000 with the embattled Bank of New Zealand Estates Company, and it was liquidated in 1905 when its land was placed under the control of a land commissioner.
Rees's major contribution to Māori land policy was made as chairman of the 1891 Native Land Laws Commission. His recommendations were followed by the Liberal government, and Crown pre-emption was to prove far more effective in alienating Māori land than co-operative trusts run along the lines of limited liability companies.
In between his Māori land ventures Rees found time to promote the East Coast region. His major achievement in this respect when out of Parliament was to draft a Gisborne Harbour Board Empowering Bill in 1884. When it became law it made a very practical contribution to the development of this isolated region.
Rees also engaged in pamphleteering and political theorising. He argued that a society based on mutual co-operation rather than the pursuit of self-interest would end conflict between capital and labour and avoid revolution. Rees was also a strong champion of universal male suffrage and women's suffrage. Nowhere, however, did he spell out in any detail how his ideal world would work.
In 1890 Rees returned to Parliament as a member for City of Auckland. He served in the Liberal government for three years as chairman of committees. During that time he defended Grey against the acerbic attacks of William Fox and wrote a hagiography of him with his daughter Annie Lee (Lily). His novel, Sir Gilbert Leigh (1878), had contained an earlier essay on Grey.
In 1893 Rees accused Alfred Cadman, the native minister, of using his position for personal gain. Cadman sued, inconclusively, for libel, and challenged Rees to a by-election contest. Both men resigned their seats in July 1893 and contested Rees's City of Auckland seat, which Cadman won. Rees retired from parliamentary politics and returned to Gisborne in 1894. He remained active in the local liberal association and continued to be involved in local business ventures, including promotion of the freezing and timber industries. He lived out his days as a kind of local squire at Te Hapara, where he laid down one of the first cricket pitches and tennis courts in Poverty Bay. He became something of a patron of the arts, partly because of his daughter Rosemary's involvement in theatre and writing.
Rees died at Gisborne on 18 May 1912; his wife, Annie, died in 1918. The complexity and diversity of Rees's character and political life make an overall assessment of him difficult. His pomposity and high moral tone, and his gross mismanagement of the potentially worthwhile trust experiment, make him an unattractive figure. Yet his attempt, however flawed, to deal with a perplexing problem, was among the factors that influenced the evolution of Liberal land policy in the 1890s.