International Andalusian and Lusitano Horse Association website gives you some nice history on the breed.
Here's a fun animation clip of an Andalsian doing a piaffe. I got this clip on Wikimedia Commons which is a very nice site for images that are available for use by the public license-free.
As I mentioned before, when you cross an Andalusian with a Quarter Horse like Solana's dam:
Ernest Expression ("Notteea"), you get an Azteca foal. The American Azteca Horse International Association website has a nice description of this relatively-speaking new breed (only dating back to the 1970's).