After Terry's 'Deus Vult' had tackled the First Crusade, I thought that the Third Crusade might make a similar subject for a megagame. The game began in 1189 after the fall of Jerusalem and the set-up involved the Europeans as three national teams - England, France and the Holy Roman Empire - preparing and then launching the crusade. In the meantime, the Sicilians, Italian maritime republics, Templars, Hospitallers and remains of the Kingdom of Jerusalem tried to stave off Saladin and his Empire, but there were complicating factors of the Byzantine and Seljuk Turk Empires as well, and of course the Assassins.
Bits of the game (combat, logistics) worked quite well, but there were the classic medieval megagame problems of not enough to do for the minor lords and not enough internal conflict in the Ayyubid team, which made life a bit too easy for Saladin. I also wrote far too much for the briefings, and a confusion over maps led to them having to be hand drawn and painted at the last minute, which added a hand-crafted, medieval look, but wasn't ideal from a looking professional point of view. A learning experience for me.
The Crusade failed to reconquer Jerusalem - indeed, Saladin extended his control over most of the Holy Land. However, the King of Sicily, after being captured, did end up as a Christian Guardian of Jerusalem on Saladin's behalf. Rob Cooper, who played King William The Good of Siciliy, told me that he found the True Cross (a counter in the game and key Crusade war objective to recover it) in his desk drawer many years later.