If Love Were All... by John Campbell

A senior British politician, married and of humble origins, has an affair with his secretary. It sounds rather familiar, doesn't it? Only the politician in question is not John Prescott, but one of the presiding geniuses of 20th-century politics, the Welsh Wizard himself, David Lloyd George, whose sport of choice was golf rather than croquet. The woman with whom he conducted a 30-year relationship was Frances Stevenson, his "Pussy", who fell under Lloyd George's spell in 1912 when was she was just 23 and he was 48, and finally married him in 1943, towards the end of his life, when the death of his wife freed him to make a commitment to her.

But then Frances Stevenson, who was introduced into the then chancellor of the exchequer's household as a private tutor to the Lloyd Georges' youngest daughter Megan, and eventually became the first woman to hold the post of principal private secretary to the Prime Minister, was clearly no Tracey Temple either. Stevenson's diary, which she kept intermittently during her years with Lloyd George, is an extraordinary document which, together with her surviving letters, presents an account of one of the most successful clandestine relationships of the modern age. For decades, one of the most famous, and for a time, most powerful men in the world shuttled to and fro between his wife and mistress, in what John Campbell rightly terms "a state of effective bigamy", without anyone - his servants, political opponents, the press, or members of his family, despite Megan's implacable hostility to the situation - blowing the whistle on him.

By the time of her death in 1972, Stevenson had already told the bare bones of her story in an autobiography, and had also collaborated with A J P Taylor on an edition of extracts from her diary. But it is only now that we are able to see the story of her love affair with Lloyd George in the round. The historian and biographer John Campbell - who commenced his distinguished career with a book on Lloyd George's wilderness years, between 1922 and 1931 - draws on a wide range of sources. He has, for instance, gone back to the manuscripts of Stevenson's and Lloyd George's writings, and restored passages previously unpublished. He uses family letters, and the diary of A J Sylvester, Lloyd George's sneaky private secretary after the First World War, who was always on hand to write up the more salacious aspects of his master's private life for his own future financial enrichment. He also exploits to good effect the surviving drafts of a Mills and Boon-type novel with a happy ending that Frances evidently wrote when she was feeling especially dejected at having sacrificed conventional family life to become a politician's mistress.

The result is a book that is by turns compulsively readable, deeply enlightening about the character of one of our greatest Prime Ministers, and fascinating, too, when one considers exactly what Lloyd George was able to get away with. Campbell works hard at solving one of the major conundrums of the Stevenson-Lloyd George ménage: was the baby daughter, Jennifer, born to Stevenson in 1929, Lloyd George's child, or was she the product of Frances's affair with J T Tweed, Lloyd George's campaign manager and an early prototype of today's political spin doctors? On balance, Campbell believes the baby was Lloyd George's, but makes it clear that neither the mother, nor the two putative fathers, were ever absolutely certain to whom Jennifer ultimately belonged. Stevenson always claimed to have adopted the child, and, even in her final years, never admitted openly that Jennifer was hers.

The dysfunctional Lloyd George family always managed to show a united face to the world, despite the domestic battles that raged behind closed doors. Lloyd George could never contemplate giving up wife or mistress. Both were essential to him. Maggie, his long suffering spouse, represented his roots in North Wales, while with Frances, who had been a school contemporary of his eldest daughter Mair, who died young, he formed a unique working partnership. The complications, which Campbell describes, of attempting to prevent the two women from bumping into one another in transit between the various Lloyd George homes, would have defeated a younger man, and sometimes descended into farce. Meanwhile, Lloyd George's interest in female flesh seems to have remained undiminished with age - farm girls, maids, typists, even his daughter-in-law Roberta, all succumbed. A J Sylvester saw him naked once, and described him as "born with the biggest organ I have ever seen".

Whether the disclosure of Lloyd George's prodigious sexual appetite, in the 60 years since his death, has dented his reputation, it's impossible to say. Lloyd George and Churchill were once acknowledged as the twin - and equal - giants of 20th-century British history. But, since then, Churchill has built up a good lead. What is certain, as this book shows and as A J Sylvester once commented, is that Lloyd George possessed a double endowment of every quality, both good and bad, compared with the ordinary man.