HMS Defence was a 74-gun third rate ship of the line

Ship of the line

A ship of the line was a type of naval warship constructed from the 17th through the mid-19th century to take part in the naval tactic known as the line of battle, in which two columns of opposing warships would manoeuvre to bring the greatest weight of broadside guns to bear...

 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...

, launched on 25 April 1815 at Chatham

Chatham Dockyard

Chatham Dockyard, located on the River Medway and of which two-thirds is in Gillingham and one third in Chatham, Kent, England, came into existence at the time when, following the Reformation, relations with the Catholic countries of Europe had worsened, leading to a requirement for additional...

.

She was converted to serve as a prison ship

Prison ship

A prison ship, historically sometimes called a prison hulk, is a vessel used as a prison, often to hold convicts awaiting transportation to penal colonies. This practice was popular with the British government in the 18th and 19th centuries....

in 1849. Defence was badly damaged by fire an accidental fire, probably caused by spontaneous combustion in a load recently delivered coal , at Woolwich on 14 July 1857. The fire was extinguished by scuttling the ship and while it was not totally destroyed the remains were broken up later.