Sir Francis Drake was an English explorer and privateer best known for his circumnavigation of the world in a single expedition between 1577 and 1580. This was the first English circumnavigation, and third circumnavigation overall. He is also known for participating in the early English slaving voyages of his cousin, Sir John Hawkins, and John Lovell. Having started as a simple seaman, in 1588 he was part of the fight against the Spanish Armada as a vice-admiral.

A privateer is a private person or vessel which engages in maritime warfare under a commission of war. Since robbery under arms was a common aspect of seaborne trade, until the early 19th century all merchant ships carried arms. A sovereign or delegated authority issued commissions, also referred to as letters of marque, during wartime. The commission empowered the holder to carry on all forms of hostility permissible at sea by the usages of war. This included attacking foreign vessels and taking them as prizes and taking crews prisoner for exchange. Captured ships were subject to condemnation and sale under prize law, with the proceeds divided by percentage between the privateer's sponsors, shipowners, captains and crew. A percentage share usually went to the issuer of the commission.