At this time England was a relatively poor and weak country. Her kings and queens were involved in a centuries long struggle with Parliament over control of the country's treasury. Parliament was reluctant to raise taxes for a powerful navy which would answer to the monarch rather than to Parliament. But as an island nation, England had an extensive private fleet, and the monarchs found in it a solution to their dilemma. There has always been a fine line between a privateer and a pirate.
Pirates commit robbery on the high seas.
A pirate ship is not commissioned by any government, and pirates capture other ships in times of peace or war. Piracy constitutes a breach of the law. Privateers are privately owned and armed vessels commissioned by a government to attack enemy vessels in time of war. Because a state of war exists, privateering is not considered breaking the law. However, because privateers often operated with invalid permits, or exceeded their authority, the line between their legitimate activities and piracy often became blurred.