The Royal Naval Hospital Haslar was a key site for the treatment of soldiers returning from Normandy, injured in action during D-Day and in subsequent fighting. Run by the United States Military during 1944 and 1945, the staff treated both Allied soldiers and German prisoners of war, before they were transferred to other hospitals around Britain.

The Royal Naval Hospital Haslar was founded in 1753 to treat British servicemen involved in war. In 1944 it played a key role in the medical care of injured soldiers returning from Normandy. They were usually sent to Haslar on Tank Landing Ships, equipped with three medical officers and sufficient medical equipment. These ships could carry up to 320 patients and were used until French ports large enough to accommodate hospital ships were secured by the Allies.

Within the first three months after the initial landings in Normandy, Haslar had received 1,347 casualties. Due to the sheer volume of injured servicemen, the basement was converted into operating theatres. In order to accommodate the numbers arriving, once stable, servicemen were transferred out to other British hospitals. The layout of the theatres was designed and implemented by Surgeon Rear Admiral Cecil Wakely.

A large, prominent building, the hospital was a prime target for German bombs. It was frequently targeted by bombers and V1 rockets. Patients were then moved into the basements below the hospital. Those who could not be moved were protected with sand bags. This would continue until Allied forces secured the launch sites in Cherbourg.
The medical staff treated British personnel and other Allied forces as well, including Empire Forces, Canadians, Americans, Norwegians, French, Dutch and Poles. They also treated many prisoners of war, some of whom were just 16 or 17 years old.
The hospital has a large graveyard, where many of those who did not survive their wounds from D-Day are laid to rest.