The facts that the French kings had amassed a large amount of land and advocated "Feudalism" as a contributed to the increase in power of the French monarchy during the 1100s.
Explanation:
The French monarchy was known for ruling strictly. Also in the eleventh century, the French kings started to become more authoritative and the influence of the Pope was becoming less.
The Feudal system also helped the King to have complete control over the whole territory and gather the maximum amount of wealth in the royal treasury.
Also, the expansion into the English Channel by William II contributed towards the French monarchy's rising power.