Sorry Terence2, I've just read my own post back and I didn't word that very well - by saying the dance was developed in the 1930s in France I wasn't suggesting that it hadn't been danced before! I was trying to make the point that the dance didn't become popular in France until that late stage and has its orgins firmly in Spain and Spanish culture. Then at that later stage the French developed it further - giving the current French names to the figures etc, as it become popular at that stage in France.
As you quite rightly say - it had been danced much earlier than that, although it wouldn't have been the paso we're used to seeing on the dance floor now!