489 years is too long…

For my English class on Witchcraft and Magic in the Renaissance, I had to watch a silent film called The Passion of Joan of Arc whose script is based on the court transcripts of Joan of Arc's trial and execution.

The short version of her story is that Joan heard the voices of saints telling her to save France, and she not only aided the French army in the Hundred Years' War, but also (indirectly) helped King Charles VII become coronated. However, she was captured by the English, tried for heresy, and executed by burning at the stake. A fuller summary of what happened is here: http://en.wikipedia.org/wiki/Joan_of_Arc

From Joan's responses to the judges' questions, her faith is clearly strong, and she views her service to G-d humbly. It is clear that her trial is heavily motivated by politics (the hatred between England and France, the issues of Charles VII's succession, the desire to bring down a national hero of France…), and the Holy See found her innocent 24 years after her death, declaring her a martyr.

Understanding that it takes a long time for someone to be canonized, I still don't understand how it took the Church 489 to canonize Joan of Arc, especially given how much she was respected in France before and after her death. Even though I'm not Catholic, I feel like it shouldn't take half a millenium for someone so genuinely religious to get canonized… I wonder what made it take so long??