At what point in history did the English stop seeing the French as the main enemy? After centuries of warfare between the two nations, it seems impossible to believe they could be such close allies. How was this achieved?

I'd like to add a further clarification to the question. Could you also elaborate on the general public perception as well? How did the average person began to trust the opposite nation, after what have been generations of warfare and mistrust? When did the public perception change and why?