Born in the early 13th Century, Sir William Longsword (Longspee) was the son of Sir William Longspee, Earl of Salisbury and his wife Ela.  Longsword was married to Idoine de Camville in June 1226, having 4 children Ela, Ida, William, and Richard.  He spent much of his life in the Holy Lands, where he died a most heroic and bloody death at the Battle of Mansor in 1249.

During the Seventh Crusade, the kings brother, namely Robert, count of Artois, wished to advance ahead of the kings forces, "his intention was alone to triumph and carry off the honour, instead of everyone, so that the victory would be ascribed to him alone, for he was extremely proud and arrogant".

After being driven back with stones by the locals in Mansor, Roberts forces retreated and William de Sounac (the master of the Templars) advised caution, saying they should wait for the kings forces. Robert was 'highly indignant and, excited and flushed with anger and pride" accused the Templars and Hospitallers of treachery, saying the Holy Land would have been theirs a long time ago if it wasn't these so-called religious warriors. William Longsword stepped up and asked Count Robert to heed the more experienced Master of Templars advise, but Robert loudly denounced William and the english as cowards. Shamed, William replied " Count Robert, I shall assuredly advance unafraid of any danger of impending death. We shall be today I fancy, where you will not dare to touch my horses tail". Unfurling banners and donning helmets they advanced.  Unfortunately the Sultan had very quickly gathered his forces after the initial attack on Mansor, and sent his vastly superior force against the Crusaders, who were quickly surrounded. 

Count Robert on seeing this shouted to Longsword "William, God is fighting against us, we cannot resist any longer. Consult your safety by fleeing, and escape alive while your horse can still carry you, lest you begin to want to when you are no longer able to"

To which William briefly replied, "God forbid that a son of my father should flee any Saracen, I would rather die happily than live unhappily".

Count Robert of Artois, believing that his horses strength would see him over the river, fled, but was weighed down by "iron and much other equipment", drowning miserably, and commiserated by no-one.  The French despaired with the flight of their count and withdrew in scattered groups.

William, against whom all the Saracens had charged, realised that it was a matter of life and death, He manfully sustained the attacks of them all, and, mutilating the bodies of many, sent their souls to Tartarus. At length the feet were cut off his exhausted horse but he still severed the heads, hands and feet of some of his assailants".

Finally after enduring many blows and wounds and having lost blood, he was overwhelmed by stones and began to fail, and he breathed out his soul, manifestly to be crowned a martyr. With him perished his standard bearer Robert de Vere, a distinguished knight, and a great many englishmen who had followed his banner from the beginning.

His mother Countess Ela, abbess of Lacock had a vision on the night of the battle, seeing a fully armed knight received into the open heavens, also hearing the words "William, your son".

There are more bloody accounts of his death, with Longsword being unhorsed because of his foot being cut off, then having one hand severed, carrying on fighting left handed, with his standard bearer also loosing a hand, then Williams' men throwing themselves over their lords body to protect him from mutilation.

(Extracts from the Chronicles of Matthew Paris)