Matilda of Canossa has, at the hands of history, suffered the fate of many women – been dismissed in a footnote as a weak and wilful character, buffeted by fate and frequently reacting irrationally – and what’s more, the mistress of a pope. (That despite the fact that her bones were the first to be laid in St Peter’s in Rome that belonged to neither a pope nor and saint.) And that’s despite the fact that the last bit of the traditional insulting portrait is almost certainly true – when a charismatic, powerful and politically adept man of 50, and a strong-minded woman who’s determined never to be forced back to live with the husband she hates spend years in close proximity, and six months alone (well except for the servants of course) in an isolated mountain fortress, it seems pretty fair to assume what happened. (And the warmth of the surviving letters between them certainly do nothing to dispel that conclusion.)

But Michele K Spike argues, powerfully, in Tuscan Countess, much else that has been written about Matilda is so much tosh. After all here was a woman destined, it seemed, by her time, the 11th century (running a little way into the 12th), to live her life as a pawn.

In the northern Italy of her time, part of the German empire, under Salic law, which allows inheritance through the female line, but not by females. So although Matilda is the daughter of Bonifacio, the Lombard count of Modena and Reggio and duke of Tuscany, hen she was left fatherless by a “hunting accident” – such “accidents” were astonishingly common at the time – popes being almost equally as prone as noble leaders to sudden, unexpected demises – she was left stranded. She was formally betrothed to the son of a rebellious noble (to whom her mother was hurriedly married, despite them being first cousins), a move perhaps related to suspicions that the German King had a hand in the “accident”. Nonetheless King Henry III swept down on Italy, took all of her father’s lands and wealth for himself, and took Matilda and her mother Beatrice to live at his court , under his charity, as his prisoner.

This was a time that, although the idea of law was starting to take hold, military might was really the only argument that counted, and women, everyone would tell you, couldn‘t lead armies. Society was again developing and growing after the centuries of turmoil after the Roman collapse: Bonifacio had become so wealthy by being one of the first Lombards to come down from his mountain fortress of Canossa and take interest in the scruffy Roman remnants of Mantua. He provided security for its traders, and taxed them for the privilege, and both sides flourished under the deal.

But with Bonifacio dead his daughter seemed helpless. Still this was some prisoner: a direct descendant through her mother of Charlemagne, Matilda read and wrote Latin, she spoke the precursors of German, Italian and French. Later she accumulated what was for her time an immense library, mostly sermons, essays on the Christian life, and on the letters of St Paul, many now preserved in Mantua and the monastery at Nonantola. Her illuminated gospel is in the Morgan Library in New York.

Spike is heavily dependent on the account of Matilda’s life provided by Donizone, the monk who the modern author strongly represents as in effect Matilda’s ghost autobiographer. There are omissions and apparently curious errors of fact in the text, but Spike argues convincingly that these were deliberate attempts to obfuscate and confuse – all with the aim of establishing Matilda’s right to her father’s lands, and thus right to decide their fate after her death.

That must have seen very distant when at 16 she was pushed reluctantly into marriage with “Godfrey the Hunchback”. They were together about two years, then, Spike suggests, although the evidence is thin, after she gave birth to a child that soon died. In the background of all of this – Spike follows the elevation, and usually the quick deaths of pope after pope in the struggle – is a church battle royal, between the Lombard bishops who favoured married clergy and the purchase of bishoprics, and the reforming Cluniac faction, which wanted to abolish both.

So Matilda, possibly mourning, and certainly determined not to return to her husband, lands in Rome in 1073, just as the consummate politician Hildebrand, whose family had already made a couple of popes, became one himself, despite being neither a priest nor a monk. But now he was Gregory VII, aligned firmly with the reform faction, and Matilda was not just a beautiful face, but a political opportunity, as he was to her. If she could claim her father’s lands, they could help the papacy. With the pope’s support, she had a much better chance than on her own.

And that’s just what she and her mother jointly did – while also acting as a go-between for Gregory and King Henry IV. And she was advising the pope. And he admitted it! That sent to German bishops into a spin.

The new pope was in trouble, but Matilda was setting her own course, arranging the vicious murder of her husband, to get him out of the road. That’s an adjective I wouldn’t usually use in that context – but since the method was a sword thrust through the anus while he was on a privy, it seems appropriate. Within two months, her father’s vassals, seemingly appreciating her ruthlessness, were accepting her as their governor. On June 15, 1076, “Dom Mathildae Comitissae” held court for the first time on her own..

There’s much more tooing and froing, such is typical of the turbulent politics of the time, including the famous story of how a penitent King Henri IV had to wait in the snow outside Matilda’s fortress at Canossa, with she and the pope inside, to see if his excommunication would be lifted. Gregory was deposed, despite Matilda’s best efforts. It looked like she’d be left with a few mountain-top strongholds. But she wanted more.

So for the first time Matilda successfully led her forces into battle, in guerrilla tactics that were to become her trademark: on July 2, 1084, she attacked a relaxed Lombard army at dawn, and utterly routed it (after, admittedly the full force, that she could never have taken on, had gone.

But Gregory was captive, deposed, and a week after he died, on June 1, 10085, , Henry IV issued an act depriving Matilda of lands she held and giving them to the man her husband had designated his heir. The Normans, who for reasons of their own were still supporting the Gregorian reforrms, were happy to make an alliance – indeed they sent Robert, duke of Normandy, the oldest son the Conqueror, to seek her hand, but there were important points on which their interests differed.

But she was pushing on with Gregory’s reforms, supporting bishops and priests who backed them, and funding a pamphlet war over Gregory’s memory. But it was again a military victory that was to really ensure her fame, continued fortune, and have other far-reaching effects on northern Italy. It was at Canossa, in October, 1092. King Henry Iv, raging at her resistance, brought his great force before it. But he didn’t know the mountains, and nor did his men, and when a cloud descended suddenly on them so too did Matilda and her forces; panic and confusion did the rest. And this was the effective end of Henri’s kingship – Matilda had effectively dethroned the most powerful monarch in Europe.

Spike has done fine work in recovering Matilda as a historical actor in her own right – but that’s not to say that this isn’t a text, and in interpretation, without some gaping flaws. First, and most seriously, Spike assumes that Matilda did all of this for lurve, pure lurve… which for a concept that didn’t take such a form until the Romantics, and wasn’t even developed at all by the troubadours until after Matilda’s death. That is one very large ahistorical stretch. If, however, one was to assume that Matilda’s motivation was to win power and influence, and not least control over her own life and fate, a motivation that we know has resounded through the ages among both men and women. And it’s also not much of a stretch to think that in this highly religious age, Matilda genuinely believed in the reforms that she championed.

Then there’s the church – Spike is clearly a fervent adherent of the Catholic Church. And while some of the glowing references to the modern-day church were enough to make me nauseous, those could be ignored. Where it does really matter is in going soft on the church of Matilda’s time – Spike skips quickly and carefully over the corruption, the murders, the violence – not whitewashing exactly, but not presenting the reader with a full picture.

And finally there’s the writing. Sadly, this is a story that never quite comes alive on the page: the reader can let their imagination soar with Matilda’s story, but a clunking adjective, or the painfully described “treading in Matilda’s footsteps” around Italy and German, will soon get in the way.

But still, my advice is simple: ignore all of that, for this is a story – a herstory – that every woman should know. (And man too, for that matter, particularly perhaps Catholic priests who think of the church as a man’s institution.) And this is, for the moment, is how you’re going to get into Matilda’s story. (Although there is apparently a military history by David Hay I must track down.)