The Great Man: Sir Robert Walpole, by Edward Pearce

Sir Robert Walpole, 1st Earl of Orford, was the most despicable creature ever to have occupied the position of Prime Minister in this country and that, given the moral turpitude of many of the recent incumbents at No.10, is saying something. He famously stated that every man has his price and, in a career of stupefying venality, set out to prove it. His attitude to money bordered on the pathological for, besides being the avatar of corruption in his own embezzlements and bribery, he took a Skimpole-like attitude to debts and, when pressed by creditors, feigned incomprehension. It took the high talent of John Gay and the genius of Swift even to suggest an approximation to his depravity.

Almost singlehandedly Walpole turned the Whig party into a byword for sleaze and jobbery in the years 1720-45. Edward Pearce defends him on the solitary ground that he kept Britain out of continental wars for 20 years and his remark to George II's wife Caroline are well known: "Madam, there are 50,000 men slain this year in Europe,and not one an Englishman."

Up to a point Pearce's defence is sound, but there are two things to be borne in mind. One is that Walpole could not have achieved British isolationism but for the avoid-war-at-any cost policies of Cardinal Fleury, de facto French premier after 1726. The other is that Walpole's motivation was suspect. Continental wars meant spending money, and Walpole was averse to any financial layout that did not redound directly to his own interests or that of his political party. So obsessed was he by money that he even objected to ecclesiastical preferment of talented parsons. His line was that you should only advance someone's career if they were already at the centre of a network of patronage and influence that you could use or manipulate.

There has been no proper biography of Walpole since J H Plumb unaccountably ended his partial effort two-thirds of the way through, so Pearce's sparkling and idiosyncratic take on the monster is more than welcome. It is often said that a biography should be the case for the defence, but it is not unknown for a would-be champion to become disillusioned with his subject. But how could anyone imagine there could be a revisionist case for Walpole?

To that extent, Pearce's choice of subject seems odd, but all becomes clear when the author reveals himself a consummate master of British politics, political parties and parliamentary procedure. Pearce knows how the system at Westminster works. It is hard to imagine how anyone could rival this author's unparalleled expertise on prime ministers and politics, which makes him a lucid guide through the arcane maze of 18th-century government and finance. Beyond that, Pearce has a very clear and shrewd idea of the English political culture in general. He is on to all the cant our politicians routinely spout.

Moreover, Pearce's book is very well paced, switching as it does from complicated finance (the South Sea Bubble) to Walpole's literary critics (Fielding, Pope, Gay, Swift et al) and from tedious parliamentary debates on "supply" to the high drama of foreign policy and the shenanigans in Hanoverian bedrooms.

My one criticism of Pearce at first sight seems to work in favour of Walpole's rehabilitation. As is well known,Walpole justified his despotism and brutality, most succinctly summed up in the catch-all Waltham Black Act (which virtually stated that crime was whatever Walpole said it was), by reference to an abiding threat from the Jacobites. Pearce thinks that Jacobitism was always a paper tiger and refers, for example, to the 1745 rising as "a French confection." To quote Mrs Thatcher, no, no, no. Jacobitism was a real and deadly serious threat to the Whig/Hanoverian system in the entire period 1689-1745 and, without the supernatural ill-luck it experienced, would surely have prevailed.

Walpole was therefore right to take the danger seriously, and comparisons with the "red scare" of Senator McCarthy in the 1950s or the "war on terror" today will not really work. There is much loose talk in England today about the "enemy within", but can one seriously imagine a battle-hardened army of 5,000 British Muslims marching on Derby, as in the '45? On the other hand, one can argue that Walpole was using a bugbear whose reality he could not accurately gauge anyway, and it may be that Britain was so unprepared for Bonnie Prince Charlie (who landed just after Walpole had died) simply because the "Great Man" had cried wolf once too often.

But one blemish does not vitiate an otherwise excellent volume, written with this author's trademark aphoristic wit. I particularly liked his many asides on the plus ca change theme. "The Bank of England was a little like the BBC today... enjoying privilege and primacy by charter, a charter sourly resented, railed at and conspired against." This is a fine summary of a "waste of space" human being, which deserves to become a standard life.

Frank McLynn's 'Lionheart and Lackland' is published by Jonathan Cape