5 things you (probably) didn't know about the Crusades

However, in desperate situations, whether the women had an interest in fighting or not, they simply had to find ways to defend and protect themselves. Thomas of Beverley's poem on the deeds of his sister Margaret offers a fascinating insight to a female pilgrim's fight for survival in a dangerous place. Margaret had travelled to the Holy Land on pilgrimage and was in Jerusalem when it was besieged by Saladin in 1187. The poem tells us that she was able to avail herself of a breastplate but in the absence of a helmet she simply improvised with a cauldron!

On the Muslim side, Usamah talks about an instance when a castle owned by his family was attacked and conquered by the Ismailis. The Ismaili leader tells Usamah's cousin Shahib that he will turn a blind eye if he goes back home, gathers his belongings and leaves the castle. As Shahib goes back home to collect his valuables he is startled by a figure who enters the house wearing a mail hauberk and a helmet, a sword and shield. The figure throws off the helmet, and lo and behold, it's Shahib's aging aunt. She berates Shahib for his cowardice and for letting down the family honour by considering running away and leaving all the women behind.

It is interesting that both sources were written by men, who praise women for their ingenuity without the slightest trepidation – despite the fact that these women's actions dealt a sound blow to accepted medieval gender roles!

During the crusader period medical knowledge was highly valued and constituted one of the crucial points of contact between eastern and western cultures

The memoirs of Usamah ibn Munqidh (1095–1188), The Book of Contemplation, are a goldmine of information about daily life in the Holy Land and include many anecdotes (some serious, some less so) on various forms of cultural exchange between the Latin crusaders and the natives of the Holy Land.

It would be fair to describe Usamah as a person who was ‘born’ to the crusades. Born on 4 July 1095, he spent his long and adventurous life living side-by-side with the residents of the Latin Kingdom of Jerusalem. In one anecdote, Usamah talks about an artisan from Shayzar named Abu al-Fath, whose son was suffering from scrofula [a tuberculosis infection of the lymph nodes in the neck]. While Abu al-Fath was in Antioch on a business trip with his son, a Frankish man noticed the sores on the boy's neck and offered them a remedy (“burn some uncrushed leaves of glasswort, soak the ashes in olive oil and strong vinegar”).

While the anonymous Frankish man seemed to be genuinely motivated by his wish to cure the boy, he was also keen to keep the ‘copyright’: Abu al-Fath had to swear by his religion that he wouldn't make money out of anyone that he cured using the recipe.

It appears that the remedy was indeed new to the Muslims, and as it cured Abu al-Fath's son its success ensured further circulation. The remedy was passed on to Usamah, who tells us that he himself used it on a number of sufferers. Through his memoirs, the remedy found its way to future generations.

Some crusader medical advice included remedies that were hardly palatable

For instance, the 14th-century anatomist and royal physician Guido da Vigevano offered slug soup as antidote to aconite poisoning. In 1335 da Vigevano produced a text (Texaurus Regis Francie) urging the French king Philip VI to launch a new crusade. The text includes technical plans, drawings for siege engines and a wind-propelled chariot, as well as medical advice, including the above-mentioned solution to aconite poisoning – which despite sounding unpleasant, is actually very ingenious.

Aconite, commonly known as monkshood and still found in cottage gardens, is a highly poisonous plant and during the crusader period it was used by the Muslims against the crusaders. Why slugs, though? On noticing some slugs that were feeding on aconite leaves, da Vigevano seems to have experienced a light-bulb moment. He collected and boiled the slugs, concocting a soup out of them, which he first tested on animals. After achieving satisfactory results he took some aconite and tried the antidote himself.

Da Vigevano proudly reported that while the first two doses made him vomit, by the third dose he was free of the poison. Sadly, he never found out whether it was worth going through this nasty trial, as Philip VI's crusade failed to materialise.

When all was lost and they were taken hostages, negotiation skills were all that mattered to crusaders

These skills undeniably came to the fore during the Seventh Crusade (1248–54). Initiated, led and largely financed by King Louis IX of France, the Seventh Crusade was one of the most logistically sophisticated expeditions to the East. While it held great promise at the start, it ended in abject failure.

Louis IX's acts during the crusade were documented by his close friend Jean de Joinville, who was privy to most of the negotiations and decision-making. Joinville provides us with one of the liveliest and interesting accounts in crusader history: he was obsessed with detail, blessed with a prodigious and photographic memory and had a passionate interest in clothing. To top it all, he had a barely concealed crush on Louis IX's wife, Queen Marguerite of Provence, who was also on crusade. Most chronicles of the crusades offer their audiences countless tales of individual bravery and sacrifice – Joinville does this too, but also gives us a king battling a bout of dysentery so severe that a hole has to be cut in his drawers.

After a doomed expedition up the Nile to take the town of Mansurah, the crusaders try to retreat to Damietta but are forced to abandon the attempt. Joinville's party realise that they are running out of options and have to surrender. A crusader among the group clearly sees this as an act of cowardice and argues that rather than giving themselves up as hostages they should all let themselves be slain and go to paradise. Joinville bluntly reports: “but we none of us heeded his advice”.

Instead, once he is taken hostage Joinville does everything he can think of so that his life will be spared: he strikes a kinship with a Muslim man, lies to his captors that he is the king's cousin, fabricates a relationship to Emperor Frederick II and quotes Saladin when it suits him (“never kill a man once you had shared your bread and salt with him”). In the end it's Queen Marguerite's powers of negotiation that save them: she hands Damietta over to the Mamluks in exchange for her husband’s life and Louis pays 400,000 pounds for his army to be released.

Watch: Did women go on crusades? | 60-second history with Natasha Hodgson

The royal women of the Latin Kingdom of Jerusalem played crucial roles in political life, which sometimes meant that they had to endure successive marriages

Royal marriage was an important political tool in the survival of the kingdom. The prize for the highest number of marriages goes to Queen Isabella I of Jerusalem, who married four times. All her husbands, bar one, were eliminated from the picture quite dramatically. She was forced to divorce her first husband, Humphrey of Toron, who was not only extremely reluctant to step up to the throne but also perceived to be too young, too intellectual and somewhat effeminate by the nobility. The divorce meant a loss of face for Humphrey, but at least he remained alive.

Isabella's second husband, Conrad of Montferrat, was not so lucky: he was assassinated by the much-feared Assassins, an Ismaili sect. Isabella married her third husband, Henry of Champagne, while heavily pregnant with Conrad's child and just a week after his death. This marriage lasted for five years and ended when Henry died falling from a castle window. Isabella's final husband, Aimery of Lusignan, died of “a surfeit of white mullet”: quite a preventable death.

How do we explain these serial marriages and what do we know about the woman who endured them? Was Isabella a helpless, romantic victim who was simply acting as a vessel in the transmission of legitimacy? Indeed, her life corresponds to the most turbulent period in the history of the crusader states: she witnessed the rise of Saladin and the fall of Jerusalem; she saw the Third Crusade come and go and Cyprus conquered, colonised and turned into a new kingdom.

The man who married Isabella would be king, so he had to be an experienced political ruler and an exceptional military leader. The decision wasn't Isabella's to make, however, as the barons were the active kingmakers, but she appears to have accepted their choices. By the end of her reign the kingdom had found stability and her eldest daughter's right to rule was secure.

Similar to Margaret of Beverley's cauldron-come-helmet in 1187, Isabella’s marriages can be seen as improvisations to protect the kingdom. The cauldron saved a pilgrim; Isabella's marriages ensured the survival of the kingdom at a perilous time.

Dr Aysu Dincer Hadjianastasis is a teaching fellow in medieval and early modern history at the University of Warwick