This is HMS Caroline. She was built in 1914 and served at the Battle of Jutland during the First World War. She spent the rest of the war patrolling the seas and had a platform built to launch Royal Naval Air Service and, from 1918, Royal Air Force fighter planes. She is a C-Class light cruiser and she would have had a crew of approximately 325 sailors. During World War Two she was based in Belfast and used as a headquarters ship by the Royal Navy. After the war the Royal Navy Reserve used her for training. She is one of only three surviving Royal Navy warships from the First World War and she is currently being restored in Belfast.
Read more about the Battle of Jutland and the fate of the sailors from Holyhead.