William Longspée 3rd Earl of Salisbury 1 2
- Born: Abt 1176, England
- Marriage (1): Ela Countess of Salisbury in 1196
- Died: 7 Mar 1226, Salisbury Castle, Salisbury, Wiltshire, England about age 50
- Buried: Salisbury Cathedral, Salisbury, Wiltshire, England
Another name for William was wILLIAM Longespée 3rd Earl of Salisbury.
Illegitimate son of Henry II, probably through Countess Ida.
From Wikipedia - William Longespée, 3rd Earl of Salisbury :
William Longespée, jure uxoris 3rd Earl of Salisbury (c. 1176 - 7 March 1226 ) was an English noble, primarily remembered for his command of the English forces at the Battle of Damme and for remaining loyal to King John .
He was an illegitimate son of Henry II of England . His mother was unknown for many years, until the discovery of a charter of William mentioning "Comitissa Ida, mater mea" (engl. "Countess Ida, my mother") 
This Ida, a member of the prominent Tosny or Toesny family, later (1181) married Roger Bigod, 2nd Earl of Norfolk .
King Henry acknowledged William as his son and gave him the Honour of Appleby, Lincolnshire in 1188. Eight years later, his half-brother, King Richard I , married him to a great heiress, Ela, Countess of Salisbury in her own right, and daughter of William of Salisbury, 2nd Earl of Salisbury .
During the reign of King John, Salisbury was at court on several important ceremonial occasions, and held various offices: sheriff of Wiltshire , lieutenant of Gascony , constable of Dover and warden of the Cinque Ports , and later warden of the Welsh Marches . He was a commander in the king's Welsh and Irish expeditions of 1210-1212. The king also granted him the honour of Eye .
In 1213, Salisbury led a large fleet to Flanders , where he seized or destroyed a good part of a French invasion fleet anchored at or near Damme . This ended the invasion threat but not the conflicts between England and France . In 1214, Salisbury was sent to help Otto IV of Germany , an English ally, who was invading France. Salisbury commanded the right wing of the army at their disastrous defeat at the Battle of Bouvines , where he was captured.
By the time he returned to England, revolt was brewing amongst the barons. Salisbury was one of the few who remained loyal to John. In the civil war that took place the year after the signing of the Magna Carta , Salisbury was one of the leaders of the king's army in the south. However, after the French prince Louis (later Louis VIII ) landed as an ally of the rebels, Salisbury went over to his side. Presumably, he thought John's cause was lost.
After John's death and the departure of Louis, Salisbury, along with many other barons, joined the cause of John's young son, now Henry III of England . He held an influential place in the government during the king's minority and fought in Gascony to help secure the remaining part of the English continental possessions. Salisbury's ship was nearly lost in a storm while returning to England in 1225, and he spent some months in refuge at a monastery on the French island of Ré . He died not long after his return to England at Salisbury Castle . Roger of Wendover alleged that he was poisoned by Hubert de Burgh . He was buried at Salisbury Cathedral in Salisbury, Wiltshire, England.
William Longespee's tomb was opened in 1791. Bizarrely, the well-preserved corpse of a rat which carried traces of arsenic , was found inside his skull. The rat is now on display in a case at the Salisbury and South Wiltshire Museum.
By his wife Ela, Countess of Salisbury , he had four sons and four daughters :
William II Longespée (1212?-1250), who was sometimes called Earl of Salisbury but never legally bore the title because he died before his mother, Countess Ela, who held the earldom until her death in 1161;
Richard, a canon of Salisbury ;
Stephen (d. 1260), who was seneschal of Gascony;
Nicholas (d. 1297), bishop of Salisbury
Isabella, who married William de Vesey
Ella, married William d'Odingsels
Ela Longespée , who first married Thomas de Beaumont, 6th Earl of Warwick , and then married Philip Basset
Ida, who first married Ralph de Somery, and then William de Beauchamp
William married Ela Countess of Salisbury, daughter of William FitzPatrick 2nd Earl of Salisbury and Eléonore de Vitré, in 1196. (Ela Countess of Salisbury was born in 1187 in Amesbury, Wiltshire, England, died on 24 Aug 1261 in Lacock Abbey, Lacock, Wiltshire, England and was buried in Lacock Abbey, Lacock, Wiltshire, England.)