You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
John,_King_of_England

Context:
The rebel barons responded by inviting the French prince Louis to lead them: Louis had a claim to the English throne by virtue of his marriage to Blanche of Castile, a granddaughter of Henry II. Philip may have provided him with private support but refused to openly support Louis, who was excommunicated by Innocent for taking part in the war against John. Louis' planned arrival in England presented a significant problem for John, as the prince would bring with him naval vessels and siege engines essential to the rebel cause. Once John contained Alexander in Scotland, he marched south to deal with the challenge of the coming invasion.

Question:
The rebel barons invited who to lead them?

French prince Louis