Complex sentence: The Exeter enters the harbour with cannons blazing, destroying not only French ships, but also multiple French fishing stages, effectively driving the French from Trepassey once and for all.
Split into simpler sentences: The Exeter enters the harbour with cannons blazing. When the Battle of Trepassey Harbour ended, Leake had destroyed not just French ships, but also multiple French fishing stages, effectively driving the French from Trepassey once and for all.