Sovereign of the Seas was a 17th-century warship of the English Navy. She was ordered as a 90-gun first-rate ship of the line, but at launch was armed with 102 bronze guns at the insistence of the king. She was later renamed Sovereign under the republican Commonwealth, and then HMS Royal Sovereign at the Restoration of Charles II.

A ship of the line was a type of naval warship constructed during the Age of Sail from the 17th century to the mid-19th century. The ship of the line was designed for the naval tactic known as the line of battle, which involved the two columns of opposing warships maneuvering to volley fire with the cannons along their broadsides. In conflicts where opposing ships were both able to fire from their broadsides, the opponent with more cannons firing – and therefore more firepower – typically had an advantage.