From Wikipedia
Empire of the Seas
Episode Two
The Golden Ocean
During the early 17th century England's relative naval power
deteriorated and a new threat emerged from the slaving raids of the Barbary corsairs, which the Navy had little success in countering. Charles I
undertook a major programme of warship building, creating a small force
of powerful ships, but his methods of fund-raising to finance the fleet
contributed to the outbreak of the English Civil War. In the wake of this conflict and the abolition of the monarchy, the new Commonwealth of England, isolated and threatened from all sides, dramatically expanded the Navy, which became the most powerful in the world.