Complex sentence: After vainly waiting for a promised Dutch squadron till the summer was passed, a westerly gale forced the fleet to take shelter in Torbay, where it was detained for several weeks, and the original idea of a landing in France had to be given up.
Split into simpler sentences: After vainly waiting for a promised Dutch squadron till the summer was passed, the fleet was forced, by a westerly gale, to take shelter in Torbay. It was detained for several weeks, and the original idea of a landing in France had to be given up.