The situation is equally problematic for a couple of other English legends Carpenter holds in esteem. There’s Marshal’s father William, the famed ‘greatest knight’, whose knighting of the young Henry before his coronation seems to have done him little good, and Stephen Langton, the archbishop of Canterbury, who ensured the enshrinement of Magna Carta in the nation’s legal foundation. Both men receive gingerly treatment from Carpenter. In the case of Marshal, he dutifully serves as Henry’s first regent and gets rid of crown prince Louis of France, who with the help of rebellious barons (including Marshal’s namesake son) had tried to wrest the throne from John, then from Henry.

What we’re not told is that Louis got a huge payoff and free pass to go home, ostensibly because Marshal was worried the king of France would seize his family’s estates in Normandy if Louis were captured and ransomed. The deal was bitterly criticised at the time, not least by Peter des Roches, because it represented Henry’s best chance to get some of his father’s continental lands back. Apparently Marshal got Louis to promise to return some of the lands, so when Louis became king of France in 1223, Henry sent Langton to Paris to remind him of it, but the archbishop returned empty-handed.

The back story here is that Langton’s brother Simon was Louis’s greatest friend and supporter among the English rebels. Neither brother seems to have made much effort to hold Louis to account, and Simon even remained on the French payroll long after Henry acceded to Stephen’s pleas to lift his brother’s banishment. It can be argued that no one had a chance to succeed with Louis, but important here is what Henry would have thought. Were these men serving his interests or their own? His greatest desire was to get back his father’s lands, and the two most powerful men in the realm, Marshal for the barons and Langton for the bishops, failed him here.

Of course, there’s no guarantee that such information will help readers understand Henry’s motives any better. Whatever brought him to the mess he finds himself in after Richard Marshal’s death and martyrdom (in the minds of the chroniclers) he’s got to claw his way back, and this he does remarkably well. Carpenter calls this period, the onset of Henry’s personal rule, the ‘years of success’, covering 80 pages of the king reaching consensus with his magnates, passing much needed legislation and carrying out financial reform. The emotionally starved Henry also finds a bride at this time. Craving family life, his marriage to Eleanor of Provence might be expected to add stability to the kingdom. Instead things start to get rocky again.

That’s because the foreigners are back. There’s his wife’s uncle, the first of four brothers from Savoy who found service under Henry, and a papal legate. Carpenter finds both men impressive and skilful, but he attributes their presence in England to the 30-year-old king’s fear of going it alone. They would be there to ‘succour and solace’ him in his uncertainty. No reason is given why Henry’s English ministers were unable to fill this role. It could be argued that the king never fully regained his trust in them or the bishops following the recent turmoil, and bringing in these outsiders was his way of undercutting them. Carpenter, however, doubts Henry had the intellectual capacity to scheme in this fashion. He was just a simple guy.

The next decade is a mixed bag for Henry. Carpenter praises his triumph in Wales and Ireland and the lasting peace he achieved with Scotland. He accomplished all this despite his ‘lack of martial spirit and love of a comfortable life, qualities not universally celebrated in a king’. A second chance at reclaiming Poitou brought Henry back to the continent in 1242, only to be comprehensively defeated by Louis IX at Saintes. Unlike most historians, Carpenter is not contemptuous of Henry’s efforts here. He lauds his ‘courage’ in pursuing the invasion against the resistance of his barons and credits him for conducting a vigorous coastal campaign. He does, however, indulge in a bit of schadenfreude by noting that he and his wife had one of their best meals ever in the same city from which Henry had to flee as he sat down to his own dinner.

It’s here that Simon de Montfort got in his famous dig at Henry, declaring that the king ought to be taken away and locked up behind iron bars. He was still nursing a grudge against Henry for publicly ousting him from court a few years earlier. For many historians, this is the height of Henry’s weakness, to not only lose the battle but allow his own men to insult him in the bargain. Carpenter takes a different approach. He makes this episode about Simon and his loose tongue, which his friends warned him to tone down before it got him into trouble. Indeed, Simon was the only earl to remain with Henry for the full year afterwards in Gascony. He knew he had some grovelling to do for running off at the mouth but found himself still frozen out by the time they returned to England. In the end, he had to beg the queen’s mother to help restore him to favour.

Now more than a third of the way into the book, the next one quarter is devoted to Henry’s piety and court. This is where Carpenter lives up to the boast of the jacket flap that we are able to get closer to Henry than to any other medieval monarch. We see the king’s itinerary and his life at Westminster, starting with the route he would have taken arriving by boat or on horseback. We’re given a tour of the various governmental and household departments. A surviving roll from the ‘buttery’, which supplied the wine, records that nearly 1,200 gallons of the French stuff were consumed over one four-day period. As for Henry’s other relaxations, Carpenter provides an exquisite portrait of the king’s beds, which Henry tested ‘as carefully as anyone in a modern showroom’. He was so impressed with the bed he gave his son-in-law Alexander III of Scotland that he ordered one for himself.

Since Henry had no continental empire to hold together, he was able to enjoy a sedentary lifestyle unknown to his predecessors. Carpenter maintains that Henry was ‘physically lazy’ and there’s no evidence that he liked to get his hands dirty and pitch in the way his grandson Edward II did. He was an avid decorator and his endless stream of orders for tiles, wainscoting and whatnot attests to his ‘imagination and impatience in matters great and small’. Still, the king might have bonded better with his nobles, says Carpenter, had he showed more interest in manlier pursuits like hunting and tournaments. The only outdoor sport he had any enthusiasm for was falconry, where it was just him and his birds and falconers (with whom he must have conversed in English). Inside the court he might wrestle with his jesters and play jokes on his clerks, but his temper, which he tried hard to control, always dogged his every move. ‘But with Henry, what you saw was what you got. He was not a king to feign anger for effect. And like summer storms, the anger was soon over.’

Just as piety informed Henry’s character, it was also the most important expression of his kingship. His charity was legendary even among his contemporaries. He fed between 150 and 500 paupers every day, thousands for special occasions. More than 100,000 were fed in memory of his beloved sister Isabella, with 4,000 of them alone crammed into the great hall at Westminster. He also distributed shoes, clothing and washed the feet of the poor in the spirit of Jesus Christ. The king even had a great silver basin constructed so he could get in there with them, ‘a beautiful indication of their shared brotherhood’, says Carpenter.

The thirteenth century was a time of great repression against the Jews. Henry seems to have shied away from the tougher measures enacted by Louis IX of France, preferring conversion instead. The special home he set up for converts stood on the grounds of today’s King’s College London, where Carpenter has taught for as long as he has worked on this biography. Henry siphoned off their wealth with little regard to the ripple effect it had, and he was personally involved in the case of the Lincoln Jews who were executed after being accused of crucifying a Christian boy. He acted from the best of motives, says Carpenter, but his actions made him the first European monarch to sanction belief in such crucifixions. This is not entirely true. In 1182 Philip II of France used a similar case of ‘blood libel’ to expel the Jews of the Ile-de-France. Carpenter also neglects to mention that as regent in 1218 William Marshal ordered the Jews to start wearing badges on their outer garments. Carpenter only says that the order, the first of its kind in Europe, came from the minority government.

Henry’s legacy is safest in what is undeniably his greatest achievement, the rebuilding of Westminster Abbey. He had already been on the throne for nearly 30 years when he began the undertaking in 1245. His reasons were manifold, not least because, as a natural born aesthete, he liked this sort of stuff, but he also wanted a coronation church, royal chapel, royal mausoleum and shrine for a national saint all in one. It was meant to be a political statement as well, both to the French, who were unable to manage their own all-in-one factor, and to his own barons, who were determined to increase the power of parliament at the expense of the crown. The abbey would be a reminder to all and sundry that the Plantagenets were far from finished.

These pages are bound to be the most personal for Carpenter, because a good part of his youth was associated with the abbey, where his father retired as dean. Some of his most heartfelt writing occurs over these 18 pages. He treats us to the intricate details that went into the construction which, since it continued until the end of Henry’s life, will also feature in volume 2. Although the design was influenced by cathedral building in France, the abbey was no knockoff. Its Englishness was evident in the use of Purbeck marble and the ‘shimmering grey-green framework’ it provided. There is, however, a wish that more of the abbey had been built in Caen stone because ‘in its slightly pinkish hue, it remains as sharp as ever, whereas the whiter Kentish stone has proved friable like a bad tooth’.

One feature that made the abbey unique for its age was the galleried triforium, which added a huge amount of space at the top. Carpenter believes Henry wanted it not just for the grandeur it offered, but also because he saw the abbey as a people’s church (never mind the cost of entrance these days). He wanted to pack them in for coronations and funerals, as well as have the poor attend services, which they would have welcomed, before going down to have their meals in the great hall next door. As for the people who actually built the abbey, one was a woman named Agnes who ‘supplied a great deal of lime’. Perhaps she and other women who worked on it can be seen in the sculptures of the angels ‘swinging their censers with easy grace, their beautiful faces full of calm assurance and humanity’.

The centrepiece of the abbey was to be a shrine to Edward the Confessor. Henry had adopted Edward as his mainstay and protector in the aftermath of the Hubert and Peter debacles. He wanted a ‘spiritual minister who would always be there, and would never let him down’. Edward was a king Henry could identify with because he too had been criticised for ‘foolish simplicity’. Like Edward, Henry aspired to be ‘wise and peaceable’ and found it reassuring that a successful king did not have to be ‘mighty and very bold’ in the tradition of Arthur.

The irony, of course, is that Edward the Confessor was Henry’s greatest failure. His attempts to make him the patron saint of the kingdom fell on deaf ears, probably because the next few centuries saw England consumed by war. A warrior, not a peacemaker, was wanted as the national symbol. It certainly has to be the bitterest of all the ironies of Henry’s reign. He was long criticised for being strangely bewitched by foreigners, but when he went to give the English people a saint of their own, they rejected him and chose George, a foreigner, instead. Just no making these people happy.