(Expanded from wikipedia article).

Marquis Boniface I of Montferrat came to the 4th Crusade comparatively late compared to his peers among its leadership. He was not present at Count Thibault of Champagne’s tournament at Écry in 1199, and so could not find him himself inspired by the words of Fulk of Neuilly. Nor was he a noble from the one of the provinces ostensibly loyal to the king of France. Instead he was elected to lead the crusade in 1201, after the unfortunate demise of Thibault. However, despite his differences in nationality and the longevity of his commitment, he stood as first among equals among the so-called “Crusader Counts,” for few knights and lords carried the weight of dignity and reputation that Boniface I of Montferrat had earned. Moreover, he was accounted a fine captain, a consummate soldier, a valiant knight, and a deeply capable politician. As a demonstration of his humility and commitment to the cause, it is said that Boniface even forfeited his title to his son, William VI, in order to “take the Cross” (although none would even consider failing to use the title when addressing him anyway).

As a scion of the House of Aleramici, he had an aristocratic pedigree that linked him to the Hohenstaufen (as 2nd cousin to Philip of Swabia), the Capetian (as the 2nd cousin of Philip Augustus), and the Babenberg dynasties (as uncle to Leopold V) intimately linking him to the ruling families and many of the high nobles of the Holy Roman Empire and the kingdoms of France and Sicily (including nearly all of his fellow leaders on the 4th Crusade). The Aleramici have also married into the Comnenus and Angelus imperial families of Byzantium, and have been intimately linked with the failing Kingdom of Jerusalem for decades.

In short, few could imagine a better man, short of a king, to lead the 4th Crusade.

Boniface’s youthful exploits in the late 1170s are recalled in the famous Epic Letter, “Valen marques, senher de Monferrat”, by his good friend and court troubadour Raimbaut de Vaqueiras. These included the rescue of the heiress Jacopina of Ventimiglia from her uncle Count Otto, who was intending to deprive her of her inheritance and send her to Sardinia. Boniface took her from her uncle and arranged a good marriage for her. When Albert of Malaspina (husband of one of Boniface’s sisters) abducted Saldina de Mar, a daughter of a prominent Genoese family, Boniface rescued her and restored her to her lover, Ponset d’Aguilar. Like the rest of the family, he also supported his cousin Frederick Barbarossa in their wars against the independent city communes of the Lombard League. On a short escapade with his brother Conrad, he even fought with the Byzantine Empire against Barbarossa’s army on the 3rd crusade, when it began raiding during its passage through Greece.

Boniface’s eldest brother, William Longsword, had died in 1177, soon after marrying Princess Sibylla, the heiress to the Kingdom of Jerusalem. In 1179, the Byzantine emperor Manuel I Comnenus offered his daughter Maria Porphyrogenita as a bride to one of the sons of William V. Since Boniface, like his older brother Conrad, was already married, and Frederick was a priest, the youngest brother, Renier, married her instead, only to be murdered along with her during the usurpation of Andronicus.

In 1183, Boniface’s nephew Baldwin V was crowned co-king of Jerusalem. William V went out to the Latin Kingdom to support his grandson, leaving Conrad and Boniface in charge of Montferrat. However, in 1187, Conrad also left for the East: Isaac II Angelus had offered his sister Theodora to Boniface as a wife, to renew the family’s Byzantine alliance, but Boniface had just married for the second time, while Conrad was a recent widower.

Thus, Boniface increasingly took on the demands of administrating his family lands. Most tellingly, this involved the cut-throat politics of the region. After becoming an advocate in an ally’s inheritance dispute, Montferrat was dragged into war with the communes of Asti and Alessandria. This further escalated into a war between the Cremona League (of which Montferrat was a part) and the League of Milan (which its enemies joined).

Boniface’s duties as regent in Montferrat kept him from following his brother and father to the Holy Land. William V had gone to Jerusalem to protect the rights of his grandson, King Baldwin V (son of William Longsword and Queen Sibylla), later fought in the Battle of Hattin, and spent years as a prisoner of Saladin. He died in 1191, leaving his title to his eldest surviving son. Conrad himself, having fallen out with the Angeli, also journeyed to Outremer, leading the successful defence of Tyre against two sieges by Saladin before becoming de facto King of Jerusalem in 1190. He was a noted leader in the 3rd Crusade and was finally elected unanimously as the true king just days before his assassination at the hands of the hashshashin. Boniface keenly felt the loss of his father and brother, and always claimed to feel a duty to take the cross so that he might honour their sacrifices. He was officially proclaimed Marquis of Montferrat in AD 1192.

The war between the Cremona League and the League of Milan flared up intermittently for the entirety of the 1190s, requiring the constant attention of the marquis, but Boniface found occasion to distinguish himself in other arenas. He aided his cousin Henry VI in his claim on the Kingdom of Sicily during 1194. During a naval engagement off the coast of Messina, Raimbaut de Vaqueiras saved his life when a vicious sword cut penetrated his helm, temporarily blinding him. He arranged a knighthood for the young troubadour afterwards, and the two became inseparable companions after although curiously, Vaqueiras sometimes addressed him as N’Engles (Lord Englishman) but the in-joke has never been explained to anyone, nor could anyone else ever get away with it. In addition to serving as the most prominent of his court troubadours, Raimbaut de Vaqueiras was in charge of his security and his spies. Indeed, Boniface was renowned for patronising troubadours in general, and often used Raimbaut as his intermediary to make use of their many talents, quick minds, and skill at manipulating public opinion.

Throughout the 1180s and 1190s, despite the wars, Boniface nevertheless presided over one of the most prestigious courts of chivalric culture and troubadour song. His patronage was celebrated widely in the courts of Europe, and besides Vaqueiras, visitors included Peire Vidal, Gaucelm Faidit, and Arnaut de Mareuil. Not a few of his loyal troubadours followed him on crusade, and while it was widely rumoured that the marquis used them to conduct his more underhanded dealings, few had the skill to keep up with what they were doing on his behalf.

Eventually, with the renewed war against Asti going quite poorly, Bonficace arranged a peace late in AD 1199, so that he might direct his energies to a more worthy enterprise. He voiced interest in taking part in the 4th Crusade, and also sent letters to the same effect to Count Theobald III of Champagne and his marshal, Geoffrey de Villehardouin. When the count passed away suddenly in 1201, the support of the latter worthy as well as Boniface’s own vast experience as a soldier and politician led to his universal election as new leader of the crusade.

He threw himself into the preparations, working to raise monies and further support amongst his own vassals and allies for the enterprise. This led to him sometimes having to lag behind the main body of the army, and sometimes caused people to mistake his movements altogether. It was because of his negotiations with the Pope that he was late to the lagoon in Venice, and why he was again away when the Venetians finally devastated Zara in March of 1203. There is also some confusion as to whether he was present at the Siege of Zara in November of 1202, as the Concord clearly saw him at the battle while others claim that he was headed to southern Germany to winter with his cousin Philip, King of the Germans and Duke of Swabia. The confusion may result from some trickery of Vaqueiras’, who was thought to have an uncanny knack for disguise.

Whatever the case, it would appear that it was Boniface who engineered the alliance with yet another cousin, this time the exiled prince known as Alexius Angelus, in the interests of restoring Isaac II to the throne of Byzantium. Alexius promised to pay the vexing debt that the crusade owed to Venice, and to further furnish them with more troops for their campaign in Egypt. The limitless wealth of the Byzantine treasury was legend, and a detour to Constantinople seemed to be the only practicable solution to their woes. Still, it was clear that the alliance was unpopular and even the gentle climes of Corfu failed to soothe bruised egos and quick tempers. In light of the new alliance, a ruinous number of crusaders began talking openly of leaving (and thus dooming) the expedition. He had Sir Raimbaut and the rest of his loyal troubadours making the rounds to make his case for the necessity of the detour, and he had faith that common sense and the rightness of the cause would prevail.

Lotario observed that Sir Raimbaut was being watched over by Geoffrey de Villehardouin and Matthew de Montmorency while doing his master’s work. Indeed, their protection directly saved his life when he was attacked by six Norman mercenaries from Durazzo. Sister Maude observed later in the evening that sir’s Geoffrey and Matthew were working closely with Boniface as well, and that the four of them believed that some kind of diabolic power sought to influence the course of the crusade. They were partly right of course. The attempted assassination appeared to have been at the behest of the deposed Brujah prince of Corcyra, Aglaia, who had a mind to revenge herself on Guy de Provence and his cronies. Luckily, Boniface and his allies did not discover anything about the vampires in their midst, but the pressure on the Silence of the Blood was an unneeded stress on an already delicate situation. The point was well taken though.

Over the balance of 1203, the Small Council of the 4th Cainite Crusade policed any interaction with Boniface and his people very closely. Even after Duke Guy dropped his stricture on interference with the mortal barons, the Cainite crusaders gave the marquis a very wide berth. Only Sister Farancina and Guy himself approached the pilgrims of Montferrat, but they were careful to keep away from Boniface and his inner circle.

He would lead one of the divisions in battle at the successful culmination of the First siege of Constantinople in July of 1203, and at first he was very much a mediator between his fellows and the new regime. When tensions spilled over into renewed hostilities with the Romaioi in the closing weeks of that year and then escalated further in January of 1204, Boniface’s patience with Alexius IV and Isaac II visibly frayed. Not only were they failing to pay the monies owed in a timely manner, but they seemed unequal ot the task of reining in their own people, who under Alexius Mourzophlos Ducas raided the crusader camp in Galata on a number of occasions. In February, their ineffectualness allowed Mourzophlos to mount a palace coup and have himself installed as Alexius V. Within weeks both Alexius IV and Isaac II were dead. The marquis was quick to draft a hefty ultimatum for the new emperor and when it was refused, the 4th Crusade declared war once again.

After heavy fighting, Constantinople fell on the 12th of April, 1204. Of the magnates of the crusade, Boniface knew the city best, and after making his camp close to the burnt Latin Quarter, rode hard for the Palace of Bucoleon the next day. Throngs of cityfolk turned out to cheer him on, both expecting that he would be their next emperor and hoping that he would stay the hand of his wrathful and greedy fellow pilgrims. They were wrong on both counts, for Boniface knew that the former development would be dealt with in due course, and the latter could not be stopped. Indeed, the Great Sack of Constantinople had already commenced.

For his part, the marquis did indeed take possession of Bucoleon, and placed the ladies there under his protection. This served to prevent any harm to them, but also placed them as valuable hostages in his power. Among those ladies were Agnes of France (sister of King Philip Augustus, widow of Alexius II and Andronicus) and Margaret of Hungary (sister of Kings Imre and András II). He also seized the extraordinary wealth that was to be had in the palace, which recompensed him many times over for the entirety of his expenses on the crusade.

Unexpectedly, Boniface’s fellows ignored his claims and instead engineered the election of Baldwin of Flanders to the throne. He was incensed at the raising up of his rival, and disinclined to cooperate with him. However, after considerable tensions over the balance of power in the newly christened Latin Empire of Byzantium over the remainder of the year, Boniface was instead made King of Thessalonica in August of 1204. The city and territory surrounding it had willingly submitted to the Emperor Baldwin months earlier, so its defences, riches, and lands were very much intact. The second city of the old empire in both population and wealth, it was a good prize, and so Boniface relented in his ambitions. He also wed the Dowager Empress Margaret, thus gaining a potential alliance with the newly enthroned András II of Hungary, furthering the strength of his position. The matter of his station settled, he then busied himself expanding his lands to the south and west, hungry to seize as much territory for himself before Baldwin could get there first.

The fortunes of the new Latin Empire fled soon thereafter. Adrianople and Didymoteicho rebelled in the new year, and the Emperor Kaloyan of Bulgaria came to their defence as the Latin armies marched. The resulting disaster of the Battle of Adrianople would see the capture of Emperor Baldwin as well as the death of Louis of Blois and much of the Latin Imperial army. For several years Kaloyan waged war on Thrace and Thessaly, destroying several prosperous cities, and the Kingdom of Thessalonica and the Latin Empire were constantly at war.

Between 1205 and 1207, Boniface never had the opportunity to take his ease and build his new kingdom, instead spending nearly all of his time in the saddle. The early favour the people of his new realm gave him was squandered by the excessive taxation that he required to fight his wars, and on several occasionas he had to put down revolts among his own subjects as well as simultaneously defend his restful lands from the Bulgarians. His queen, Margaret, did furnish the 55 year old king with an heir, Demetrius, and he also rejoiced at the marriage of his daughter, Agnes, to Henry of Flanders, Baldwin’s brother and successor to the imperial throne.

The camp of King Boniface of Thessalonica was ambushed by the forces of Kaloyan on 4 September 1207. He rushed to his horse with a lance and, unarmoured, threw himself into the fray only to be struck by an arrow to the inside of his arm just below the axilla. When he fell from his horse and expired from blood loss, many of his men fled the field and his body was abandoned. Raimbaut de Vaqueiras however, did not abandon his friend, and is thought to have been lost in the same battle. The head of Boniface was sent to Kaloyan, and is one of a number of grisly treasures that the Tsar cherished before his own demise attacking Thessalonica 2 months later.