It's called the English channel, because every time in the last 953 years that someone has tried to sail across it to try and invade England they've been given a jolly good kicking and sent packing.
The name is merely convention, but one earned through almost a millenia of arriss kicking. If the Armada hadn't been given a jolly good drubbing by Drake's boys it would doubtless be named the Spanish Sewer, or somesuch.
Now, what about all the French place names in Algeria? See - history is as history does, and right or wrong it is still history.