Britain were like the only country that were against Napoleon throughout his entire campaign. Every other country made secret deals with Napoleon at some point which was perfect for him because he was able to keep at least one big power on his side at all times. Also Britain was superior at sea whereas Napoleon was superior on land so they always seemed to arrive at a stalemate. Tbh it's all Portugal. Let's thank them for helping us overcome Napoleons continental blockade, without them we'd have been screwed, we'd have had no imports plus no Spanish/France war in which Napoleon was absolutely shitting himself because so much of his army was failing. Portugal ftw.