The present day ruins of Chateau Domfront, one of the castles in Normandy promised to Godfrey, Duke of Lower Lorraine, on his marriage to Empress Matilda
The Robertian War of the Norman Succession is used to talk about the period from 1131, and the recognition of the Dowager Empress Matilda as Heir in England, to 1138 and the death of William Clito, legitimatist claimant to both England and Normandy. The two were cousins, both grandchildren of William the Conqueror, but William argued his legitimacy as the male line claimant (in right of his father, and from 1134, in his own right) whilst Matilda was female. That seemed to be William's big argument when it came to both crown's, but in favour of William, his brother-in-law was King of France whom the Duke of Normandy was nominally in suzerainty to. This had been a sore point to both William's and now Henry and William Clito leveraged this connection, now it wasn't just William vs Matilda, it has become France vs Matilda, and after a furious communication with her father, France vs England.
And so the Robertian War of the Norman Succession was a proxy war between France and England. In the midst of the war, Joanna of Montferrat provided William with two daughters, Gisela (after her maternal grandmother, Gisela of Burgundy) and Azalais the Posthumous (after Azelais del Vasto, former Queen of Sicily and Jerusalem) and when the latter was born, sometime in Early 1139, Matilda and Godfrey had not been blessed with children. If Matilda died, then the infant Gisela might be used as a figurehead for Robertian factions and placed upon the throne. After her father's death in Late 1138, she was the legitimate claimant. Joanna had fled to the French Court where her seventeen year old nephew, Louis the Young, was now King, to give birth, and she found comfort from her sister, the Dowager Queen, and was present as Louis' marriage to Eleanor of Aquitaine, elder sister of the twelve year old, William (XI) the Eagle, Duke of Aquitaine.
There, the Dowager Queen and her sister came into the social circle of Adeliza of Louvain, and her English husband, William d'Albini, a relative commoner that the pair found beneath their station. Joanna might not be able to push her infant daughters claim, her nephew was reluctant to continue the war and Godfrey, Duke of Lower Lorraine and King Consort of England was holding Normandy and had reinforced border castles such as Domfront, Exmes and Argentan, as well as Rouen and Barfleur. But William was handsome, and Adeliza was useful, her brother, after all, was now the King Consort of England.
And then, with much rejoicing, Empress Matilda fell pregnant.