Pirates - A Treasure Chest of Information

"Drake was known as a 'privateer.' A privateer was one who attacked ships and towns of his country's enemy. He usually had a 'Letter of Marque,' issued by the Queen which said that he was instructed to rob by command of the Queen. Drake frequently committed piracy without a Letter of Marque from the Queen, but these indiscretions were overlooked by his country and he became a national hero in England.

The Elizabethan pirates disrupted the flow of gold and silver from the mines of the Americas to Spain. Most pirates had no allegiance to any Queen or country. They simply had a desire to plunder vast riches from Spanish ships." (aar! there be more at the link, me hearties!)
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