The sea dogs, as they were disparagingly called by the Spanish authorities, were privateers who, with the consent and sometimes financial support of Elizabeth I of England (r. 1558-1603 CE), attacked and plundered Spanish colonial settlements and treasure ships in the second half of the 16th century CE. With only a license from their queen to distinguish them from pirates, mariners like Sir Francis Drake (c. 1540-1596 CE) and Sir Walter Raleigh (c. 1552-1618 CE) made themselves and their backers immensely rich. Elizabeth and her government, unable to trade legitimately with the colonies of the New World as Philip II of Spain (r. 1556-1598 CE) held on to his monopoly, turned instead to robbery as a means to persuade the Spanish king to change policy. As Anglo-Spanish relations deteriorated, the privateers became a useful tool in reducing the wealth of Spain and disrupting Philip's plans to build his Armada fleet with which he hoped to invade England. Although in some respects successful, especially with such captures as the great treasure ship the Madre de Deus, the privateers did not work together sufficiently to pose a serious and sustained threat to Spanish shipping, which began to use armed convoys to great effect. For a few decades, though, the fast English ships bristling with cannons and captained by audacious adventurers, caused havoc on the High Seas.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1576/the-sea-dogs---queen-elizabeths-privateers/.