Lord Lexden is the Conservative Party’s official historian. His website can be found here.

December 2018 will bring the centenary of what was by any standard a landmark general election. The transition from a truly terrible war to peace was in itself momentous. So too was the scale of change in the electoral system since the previous contest eight years earlier. A fourth parliamentary reform act had just been passed, far larger in scope than any of its three nineteenth-century predecessors.

The 1918 Reform Act extended the franchise much further than all the earlier ones put together, conferring the vote on all men over 21, irrespective of wealth, class, or housing tenure (issues over which reformers and their opponents had for so long haggled), and to most women over 30.

For men who had seen active service, the voting age was reduced to 19. Postal and proxy votes were introduced for all members of the armed services, but for no one else (civilians had to wait another 30 years). The British electorate of 1918 numbered 21.4 million voters, compared with the 7.7 million of 1910.

More than three-quarters of the electorate of 1918 had never cast a vote for any party in a national election before. For the first time, polling took place on a single day throughout the country instead of being spread over two to three weeks. A handful of women stood as candidates for the first time, one of whom, representing the abstentionist Sinn Fein Party in Ireland, was elected.

Though few in the unsettled circumstances of 1918 predicted it, the future belonged to the Tories, known generally as Unionists in this period, as they strove to prevent Ireland passing under the unfettered control of its nationalist politicians. In the years between the world wars the Party won five large Parliamentary majorities, and no other Party ever won a majority at all.

The 1918 election brought them the first of these successes as part of a coalition under Lloyd George. It was nicknamed the coupon election, a mocking reference to letters of endorsement sent to candidates officially approved by the coalition. The Unionists, who won 335 seats, could perfectly well have governed on their own in a Parliament which 73 Sinn Fein members refused to attend, substantially diminishing the combined forces of the other parties even if they could have brought themselves to act together, which was in practice inconceivable.

Nevertheless, only a small number on the right of the Party urged it to assert its independence either during, or after, the election. It would take four years more to convince a majority of Unionists that the Party should face the future on its own, as the critics of Lloyd George, who were always present – he had after all been the Liberal that Unionists hated the most before 1914 -achieved overwhelming predominance in their Party.

In 1918, their voices were muted. A resort to the polls was conceived in the spring of that year as a khaki election to provide Lloyd George’s coalition government, which relied on Unionist MPs for its existence, with a mandate to see the war through to a conclusion, which few at that point expected before 1919 (Lloyd George himself thought it might well continue into 1920).

A sudden change in the tide of war in the autumn of 1918 converted the contest into a victory election, with the coalition government offering a substantial programme of post-war reconstruction, though the prospect of punishing the Kaiser and his defeated country seems to have been uppermost in the minds of many electors, stimulated by a lurid and irresponsible press campaign.

The Unionists as a whole were, then, entirely content to remain in alliance with Lloyd George and those Liberals who supported him. They had both high and low motives, like most British party politicians throughout history. Foremost among the worthy considerations in their minds stood patriotism, which Unionists liked to claim as their special, defining characteristic. After 1915, this meant positive enthusiasm for working with other Parties to ensure Britain won the war and remained a great power.

It was with intense satisfaction that the Unionists had turned from the vacillating Asquith to the dynamic Lloyd George as coalition partner at the end of 1916. By and large they did not share Lloyd George’s deep distrust of Field Marshal Haig’s conduct of the war in Flanders – indeed, Unionists accepted high casualty figures with rather shocking equanimity – but they admired his vigour and virtuosity as a strategist.

They were conscious of the spectacular victories that had been achieved in Mesopotamia and Palestine since 1916. Under Lloyd George’s coalition, the map had turned redder than ever before. Unionists spread the Union Jacks which always adorned their Party platforms with especial pride at the 1918 election.

Furthermore, Unionists could not see how a nation, deeply troubled at home, could avoid severe dislocation without Lloyd George and what was widely believed to be his special rapport with the working classes. Acute industrial unrest with violent scenes on Clydeside, Sheffield, and elsewhere made it seem imperative in 1918 to keep the brilliant Welsh wizard at the helm in order to prevent a socialist revolution, a fearsome spectre by which Unionists – and indeed many others – were haunted.

It seems the stuff of fantasy now, but it was not so then. At a conference in Leeds in 1918 British trades unionists (including that embodiment of moderation, Ernie Bevin) resolved to set up workers’ and soldiers’ soviets on the Leninist model. At the 1918 election the Labour Party gained nearly a quarter of the vote with an avowedly socialist programme. This was not a time for the Unionists to separate themselves from Lloyd George at the very height of his power in public affairs at home and abroad.

Base considerations of party politics pointed to the same conclusion. Nothing was so obviously in the Unionist interest than a divided Liberal Party – and the deeper the division the better. There was no surer way to Unionist ascendancy in British politics than via a broken Liberal Party.

Unionists had endured years of nail-biting negotiations between Joe Chamberlain and William Gladstone after 1886 before they knew for sure that the great radical had nowhere else to go, except into their arms. Lloyd George did not keep them guessing. In 1918 the Unionist leader, Bonar Law, referred to him privately as a second Joe, a man who had been firmly captured by the Unionists.

The alliance was sealed by mutual admiration. Bonar Law and his main Unionist cabinet colleagues – Curzon, Balfour, Austen Chamberlain and F.E. Smith – thoroughly enjoyed working with Lloyd George and some of his principal lieutenants, Winston Churchill above all.

That feeling did not lessen with the passing of the years, despite growing criticism of Lloyd George among junior ministers, on the Unionist backbenches, and in the Party at large. Coalition became for the Unionist leaders a way of life; they saw it as bringing together the finest Liberal and Unionist talents in government. This elite, they believed, should rule for ever. They never wanted coalition to end.

158 Liberal candidates received the coalition coupon at the 1918 election; 253 other Liberals stood without the coupon. This represented a breach so deep that a fully and enthusiastically reunited Liberal Party was an impossibility in the foreseeable future.

The implications were obvious to those Unionists, an ever growing majority, who did not believe in permanent coalition with Lloyd George. Their Party was now ideally placed to build a new political dispensation by attracting the votes of demoralised and bewildered Liberals through a genuine and deliberate promise of broad, generous social reform, and by treating Labour as a parliamentary rival, not as a threat to the established order.

Stanley Baldwin, the softly spoken enemy of class conflict who came to hate coalition government, seized this historic opportunity after dispatching Lloyd George into the political wilderness at the famous Carlton Club meeting of October 1922, where the Unionists formally repudiated both the Welsh wizard and their own arrogant leaders who believed in permanent coalition.

Baldwin knew how make Toryism attractive to Liberals whose world had been turned upside down in the years of Lloyd George’s ascendancy. The 1918 election was a crucial staging-post on the road to inter-war Conservative Party hegemony.