Roy MacLaren's Empire and Ireland is two books in one: it is both a readable and informative biography of the Canadian-born British politician Sir Hamar Greenwood (1870–1948) and an interesting and significant contribution to the history of the Irish Revolution. While not an important politician for most of his career, Greenwood was the last chief secretary for Ireland: he accepted this poisoned chalice in 1920, in the midst of the Irish War of Independence, and he drank its contents to the lees, holding this office until it was abolished in 1922 and killing his political career in the process. He is a notorious figure but also a mysterious one: He is remembered in Irish history as the minister who defended the British government's fight against Irish freedom—as the man who seriously suggested, for example, that the people of Cork had burned and looted their own city center in December 1920—but, like Dublin Castle's equally notorious police adviser, Sir Henry Hugh Tudor, Greenwood left few documents for historians to study. His personal papers (and more importantly, his wife's) were destroyed in the Blitz. MacLaren therefore has done us all a favor by tracking down the remaining evidence and piecing together the life story of the much-maligned final chief secretary.

In the first hundred pages of the book, MacLaren traces Greenwood's rise to the chief secretary. Greenwood was an accidental Briton: he was born in Whitby, Ontario, the son of a locally prominent lawyer and municipal politician; and he studied at the University of Toronto, where his classmates included two future Canadian prime ministers, William Lyon Mackenzie King and Arthur Meighen. But his prospects for a legal career in Canada were blighted by his leadership of a student strike in 1895, and after graduation he immigrated to the United Kingdom, where he campaigned for temperance, promoted emigration to Canada, and got involved in Liberal politics. A liberal imperialist in outlook, Greenwood was elected to the House of Commons in the Liberal landslide of 1906, lost his seat in January 1910, but gained another in December, which he held until 1922. Ambitious for office, he rose through the Liberal ranks and was given junior positions in the postwar coalition government before becoming chief secretary for Ireland in April 1920.

In the next 130 pages MacLaren covers the two years that Greenwood served as chief secretary: they are the heart of Empire and Ireland, and MacLaren provides a number of interesting insights into the making of British policy during the Irish War of Independence. Like other historians before him, MacLaren argues that this policy was largely the work of the prime minister, Lloyd George, and was chiefly constrained by the nature of the coalition government: the Conservative-Unionists were hostile to the movement for Irish independence, and they had enough seats in the House of Commons to form a government without Lloyd George and his coalition Liberals. The prime minister was not willing to break up the coalition over Ireland, and as a result, he pursued an indecisive policy that combined limited concessions with limited repression: the former was embodied in the Government of Ireland Act, the latter by the Black and Tans, the paramilitary Auxiliary Division, and a permissive attitude toward violent reprisals by the crown forces against supporters of the Irish Republic.

As chief secretary for Ireland, Greenwood became British policy's most prominent public defender; but, according to MacLaren, Greenwood did not play a large part in making this policy. In fact, the prime minister was more inclined to listen to Greenwood's ambitious and intriguing wife, Margo, with whom Lloyd George may or may not have been having an affair. (MacLaren reproduces the few remaining scraps of Margo Greenwood's diary for this period, and they are tantalizing.) Machiavelli argues that princes need hatchet men: they should, he says, reserve popular measures for themselves while delegating unpopular measures to others. This latter was the role that Lloyd George had written for Greenwood—and Greenwood played it so well that Irish nationalists have cursed his name ever since. But the reader may be surprised to learn that while he was loyally stonewalling the government's critics in the Commons, the liberal-imperialist Greenwood was privately advocating dominion home rule for Ireland and arguing in favor of releasing the Strickland Report on the Burning of Cork to the public.

According to MacLaren, Greenwood expected to be given the Home Office as his reward for services rendered, but ironically, once both sides in the War of Independence had been worn down to the point that they were willing to negotiate a settlement, the chief secretary now came under attack from the Conservative-Unionists. And in the end, once the Anglo-Irish Treaty had been signed, the coalition broke up, and the new Conservative-Unionist government disposed of both Lloyd George and Greenwood. The remaining hundred pages of Empire and Ireland are devoted to Greenwood's disappointing post-ministerial career: he lost his seat in Parliament in 1922, gained another in 1924, and though he kept it until 1929, he never held office again.

No book is perfect, and Empire and Ireland has the faults of its virtues. Much of its value and significance lies in MacLaren's detailed description of the Irish War of Independence from the perspective of British high politics. But as MacLaren himself admits, Greenwood was never more than a supporting character in the revolutionary drama: as the prime minister's human shield in the House of Commons, the chief secretary took all the responsibility for the government's Irish policies, but was given virtually no power to change them. And in the end, while he was one of the signatories of the Anglo-Irish Treaty, the chief secretary was excluded from the treaty negotiations at the insistence of the lord chancellor, Birkenhead. As a consequence, for more than a third of the book, Greenwood himself is often upstaged by the more important characters in the story of the Irish Revolution, and sometimes even fades into the background of his own biography. After explaining, for example, why Lloyd George was willing to sacrifice Greenwood in exchange for Birkenhead's participation in the Treaty negotiations, MacLaren then devotes three pages to discussing why the Conservative-Unionist lord chancellor was himself willing to participate, while poor Sir Hamar languishes offstage—much as he was forced to do in real life. But in spite of this (perhaps unavoidable) problem, MacLaren's book is indispensable reading for historians of the Irish Revolution and recommended reading for anyone with an interest in British and Imperial history during this period.