Battle of Trafalgar re-enactment

Admiral Nelson

Yesterday off the coast of Britain, thousands watched a re-enactment of the battle Battle of Trafalgar. For those who don't know what this is, it was a sea battle in 1805 off the coast of Trafalgar, Spain. The British Royal Navy, under the command of Admiral Nelson, destroyed the combined sea forces of France and Spain. It gave Britain command of the seas for 200 years.

Now what has me puzzled is why on earth did France and Spain agree to participate? That would be like the US navy agreeing to reenact 1941's Pearl Harbor attack.