The most inmediate consecuence of the existence of a son born from the doomed marriage between Louis VII of France and Eleanor of Aquitaine was that the "Angevin Empire" probably wasn't existed in the way that all knew:
1.- According to the Feudal Law, the eldest male heir/son had supremacy over his other siblings. If Philippe, son of Louis VII and Eleanor existed, he had the first right of succession in Aquitaine over ALL the offspring of the Duchess from her second marriage with Henry II of England.
However, the right of inheritance wouldn't imply that Eleanor agrees with this -is known that she was an independent and strong character, and in addition, her personal feelings would also influenced to her: after her divorce from Louis VII, the physical custody of their two daughters (Marie and Alix) was granted to the father, and logically, Philippe, as Prince Heir of France, also remained in France. This would mean that Eleanor had little, or any real intervention in his son's life, so she perfectly could preferred her children with Henry II (especially Richard) at the moment to a likely battle for her patrimony.
2.- Without the power of the Aquitaine domains to the next generation, the Plantagenets probably remained under the vassalage of the Capetians.
Henry II, as consort of Eleanor was Duke of Aquitaine, Gascogne and Count of Poiters by marriage, and thus, at least during his lifetime (1152-1189) extremely more powerful that his Lord the French King. The question is: what happened after Henry II died?...The most probable scenario was a succession war between Eleanor's sons (French vs English) over Aquitaine. In this case, King Richard I of England (in the case that Henry the Younger died in 1183 of course!) could have some advantage because, as Count of Anjou, Maine and Duke of Normandy (inherited by his paternal grandparents Geoffrey V and Matilda) he could mantain some resistance over Aquitaine and surrounded this land by sea and land. By the other hand, King Philippe II of France (remember, a different from the real!) probably could use the absence of Richard I from France at the time of Henry II's death to take Aquitaine and proclaimed himself Duke.
3.- A regency of Eleanor over France in the case that Louis VII died in 1160 (this year could be more proper that 1150 because the divorce between them was in 1152!) seems unlikely.
The French nobles could consider extremely dangerous that the Queen of England would became also in Regent of France: this would be the perfect excuse of Henry II to directly interfered in the French politics. Probably, the most likely Regent would be the next legitimate male relative of the young King, in this case one of his four paternal uncles (Archbishop Henry of Reims, Count Robert of Dreux, Bishop Philippe of Paris and Lord Peter of Courtenay). In my opinion, the ideal candidate would be Count Robert, as the eldest laic brother.
What do you think?, from here could start an interest thread......