Admiralty in the 16th century has organized the fleet into squadrons from at early 13th century and certainly during the 16th century. In 1560 three squadrons were operating in the Channel, Irish Sea and North Sea Until the 16th century, admirals were high officials under kings, and were charged with protecting the realm from sea attack. The English navy's Narrow Seas Squadron also called as the Eastern Squadron mainly operated in the two seas which laying between England and Kingdom of France (the English Channel particularly the Straits of Dover) and England and the Spanish Netherlands later the Dutch Republic (the southern North Sea). Include:
Admiralty in the 16th century and a permanent core of purpose-built warships, originated in the early 16th century during the reign of Henry VIII. Under Elizabeth I England became involved in a war with Spain, which saw privately owned ships combining with the Royal Navy in highly profitable raids against Spanish commerce and colonies. In 1588, Philip II of Spain sent the Spanish Armada against England to end English support for Dutch rebels, to stop English corsair activity and to depose the Protestant Elizabeth I and restore Catholicism to England. The Spaniards sailed from Lisbon, planning to escort an invasion force from the Spanish Netherlands