in about 1206-7 John, for reasons unknown, started to perse
cute William de Briouze and others. Over the next several y
ears things went from bad to worse. In 1208, John demande
d hostages from William and Matilda (Maud) apparently sai
d that she wouldn't deliver up her sons to John as he had m
urdered his nephew Arthur. After this things got really ba
d and William and his family were forced to flee to Ulste
r (William was Lord of Limerick). In spring 1210 John prepa
red an expedition to Ireland and Matilda fled with her son
s to Scotland (William was in Wales at this time). Matild
a and the children were captured by a Scots lord and hande
d over to John. Matilda and the eldest son (William IV) wer
e imprisoned, and were never seen again. The common report
, recorded in several monastic annals, was that they had be
en starved to death.
For a fuller version of this I would suggest you read :
King John by W.L. Warren, Eyre Methuen, 1978
The Feudal Kingdom of England 1042-1216 by Frank Barlow, Lo
ngman, 1985