William Clito, son of Robert Curthose, became the last remaining male-line heir of William the Conqueror in 1120 when his cousin William died in the White Ship Debacle. Despite William Clito being the logical heir of his uncle Henry I, he remained in exile in the court of the French King Louis VI. Louis VI viewed William Clito as his protege and a vessel to attack the growing might of Henry I's kingdom. To help his protege launch raids on Normandy, William Clito was granted extensive estates in Vexin in 1126 following his marriage to the French Queen's half-sister.
William Clito was appointed the new Count of Flanders following the death of Charles the Good in 1127. This provided William Clito with one of the richest and most powerful fiefdoms in Medieval France and the perfect base to launch attacks on Normandy or even England. Of course, the County of Flanders was heavily contested with numerous claimants receiving support from Henry I. Despite some early setbacks, William and his nobles had begun to beat back Thierry of Alsace and his benefactors in Burges and Ghent. Thierry was in fact besieged in Alsat by William Clito when the young Prince died at 25 of a gangrenous wound.
What are some short-term and long-term ramifications of male heir of William the Conqueror when Henry I dies in 1135? Will this new Norman Kingdom centered around Flanders, Normandy and England be able to remain intact long-term?