he Conservative Party in Great Britain has only called itself the Conservative Party since 1830. The prime minister at the time was the Duke of Wellington, but no one thought of him as the father of the party. The political body to which the new name referred was the creation of the prime minister who held office for the exceptionally long period of fifteen years (1812–1827) leading up to the party’s solidification under Wellington and Robert Peel. That man was Lord Liverpool, whose biography William Anthony Hay has done us the great service of writing.

The quarter century of Liverpool’s career was a time of transition for Britain. Georgian laxity was giving way to Victorian rectitude. Powdered wigs were falling out of fashion, until no one wore them except Lord Castlereagh, whom everyone mocked for his old-fashioned affectation. Parliament itself was undergoing the shift from an eighteenth-century system based on patronage to a modern one based on party. Instead of a multitude of factions based around particular individuals (Pittites, Foxites, Grenvillites, Addingtonians), Parliament after Liverpool would be organized into two parties, government and opposition, each united by a common policy platform and not, as the old factions had been, by bribes.

Liverpool was born Robert Jenkinson, the only son of a widowed father, his mother having tragically died a month after his birth. He was therefore a compliant child, anxious to please the father for whom he was all in all. It was his misfortune that his father should have been not only doting but a bore, the sort of man whose recreation, in the time he could spare from his own political career, was writing a celebrated numismatics textbook. The son, too, became a bit of a prig, even as a young man. He failed to spend all of his £200 allowance his first year at Oxford, which Hay rightly calls “an achievement for an undergraduate in any age.”

The reward for his diligent good behavior was to be elected to parliament at the age of 20 and appointed Foreign Secretary at age 30. To be fair, few others wanted the job. The task awaiting the Foreign Secretary in 1801 was the negotiation of the Treaty of Amiens, that peace “which all men are glad of but no man can be proud of.” It was a Whig, Richard Brinsley Sheridan, who originated that phrase, so one can imagine how the Tories felt about the treaty. Under a barrage of criticism for having signed a truce with a menace like Napoleon, Liverpool gave “much the ablest defense of the treaty which was made in either House of Parliament,” according to the Annual Register of that year—but he was still fired from the foreign ministry when Pitt returned to office in 1804.

He had better luck at the War Office, where his achievement was getting Wellington to trust him. The general was a prickly customer, and the Peninsular War brought out his pessimistic side. He knew that many politicians in London considered the war a sideshow, hampered by feckless Spanish allies and the vagueness of Britain’s war objectives. In 1809, when Liverpool took over the War Office from Castlereagh (the only politician Wellington trusted), his field commander regarded him with suspicion. It is doubtful whether victory could have been achieved if Liverpool had not successfully coaxed Wellington into feeling confident that London would back him up—or without the 25,000 reinforcements that Liverpool, thanks to shrewd manpower reforms, was able to send him.

In 1812, Spencer Perceval was shot through the heart in the lobby of the House of Commons, becoming the only British prime minister ever to be assassinated. Liverpool was chosen as his successor not out of any overwhelming respect for his abilities but because he was the man everyone could agree on. He was well-liked, with few enemies. He was such a pacific personality that he was able to persuade Castlereagh and George Canning, who had famously fought a duel with each other in 1809, to serve in the same Cabinet, allowing his government to enjoy the advantage of Canning’s unparalleled oratory in the House of Commons and Castlereagh’s equally impressive diplomatic skills at the Congress of Vienna.

There was, however, a dark side to Liverpool’s amiability. He was deeply, almost pathologically conflict-averse. “I am quite sure if one was to drop down in a fit or be shot through the head while in his room,” Canning wrote in a private letter, “he would (if he could, unobserved) sneak out of the room and get into his carriage, ringing perhaps for Willimot [his private secretary] to take care of one.” At moments of crisis, he had a bad habit of becoming agitated to the point of tears, even to the point of fits. Hay hints that he might have been mildly autistic, “often misreading social cues,” “taking things literally,” and “fail[ing] to pick up on non-verbal communication.”

Still, he kept his nerve when it counted, for example during the notorious “Peterloo” massacre when untrained cavalry officers charged a crowd of radical protesters in St. Peter’s Fields in Manchester, killing 15. (A film about the incident, Peterloo, from director Mike Leigh, will be released by Amazon Studios next year.) Popular outcry demanded that Liverpool discipline the officers responsible, but he refused. He had seen mob violence first-hand in France in 1789, personally witnessing the storming of the Bastille at age 19, and the experience made him sensitive to the threat of revolution. The brighter side of this sensitivity was that it strengthened his commitment to reforms to ease the lot of the poor. Taxes fell by fully a quarter in the seven years after the war ended, and free trade reforms brought greater prosperity, to the benefit of all classes.

In Benjamin Disraeli’s novel Coningsby, the title character and his grandfather debate when the Conservative Party abandoned “true Toryism.” Was it with the Tamworth Manifesto of 1834, the Reform Bill, or at some other time? “We must mount higher: we must go back to ’28 for the real mischief,” his grandfather says. After Liverpool’s debilitating stroke in 1827, the party immediately entered a period of internal crisis, with half of the Cabinet refusing to serve under his successor Canning. From the perspective of 1844 when Disraeli was writing, on the eve of the party’s split over the Corn Laws, Liverpool’s long reign marked the last period of happy unity. Liverpool might not have been the spirit of the age on horseback, as Napoleon was called by Hegel, but he was the spirit of the Conservative Party at the birth of its current incarnation. With Hay’s fine book, he has the modern biography he deserves.