HMS Unicorn was a 28-gun Lyme-class

Lyme class frigate

The Lyme class were a class of two 24-gun sixth-rate frigates of the Royal Navy. They served during the War of the Austrian Succession and the Seven Years' War....

 sixth-rate

Sixth-rate

Sixth rate was the designation used by the Royal Navy for small warships mounting between 20 and 24 nine-pounder guns on a single deck, sometimes with guns on the upper works and sometimes without.-Rating:...

 frigate of the Royal Navy

Royal Navy

The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...

. She was originally ordered as a 24-gun ship to the draft of the French privateer Tyger. The third vessel of the Royal Navy to bear the name, the Unicorn, as well as which was a near-sister, were the first true frigates built for the Royal Navy. They were actually completed with 28 guns including the four smaller weapons on the quarterdeck, but the latter were not included in the ship's official establishment until 22 September 1756. The two ships differed in detail, the Unicorn having a beakhead bow, a unicorn figurehead , two-light quarter galleries and only five pairs of quarterdeck gunports, while the Lyme had a round bow, a lion figurehead, three-light quarter galleries and six pairs of quarterdeck gunports.

The Unicorn was first commissioned in March 1749 under Captain Molyneaux Shuldham

Molyneux Shuldham, 1st Baron Shuldham

Molyneux Shuldham was an officer of the British Royal Navy. He served for a time as colonial governor of Newfoundland.-Family and early life:...

, under whose command she spent her first commission in the Mediterranean until returning home to pay off at Deptford in June 1752. After repairs, she was recommissioned in January 1753 under Captain Matthew Buckle, and sailed for the Mediterranean again in April 1753. In February 1756 command passed to Captain James Galbraith, then in that September to Captain John Rawling. After active and continuous service during the Seven Years' War

Seven Years' War

The Seven Years' War was a global military war between 1756 and 1763, involving most of the great powers of the time and affecting Europe, North America, Central America, the West African coast, India, and the Philippines...

, she finally paid off in late 1763, and was broken up in 1771.