Members of the Boys were slave labourers in the Kaiserwald concentration camp in Latvia.
Kaiserwald concentration camp was operated by Nazi Germany.
The Boys were teenage and child-Holocaust survivors, who were brought to the UK after the war for rest and rehabilitation.

Kaiserwald memorial.
The camp was located in the Mežaparks Forest near the Latvian capital of Riga.
History
The camp was built in the spring of 1943 during the German occupation of Latvia.
In June 1943, the ghettos in Riga, Liepāja and Daugavpils were liquidated and the surviving Jews were taken as slave labourers. Surviving Jews from the liquidation of the Vilnius Ghetto followed in the autumn of 1943.
Smaller labour camps in and around Riga then became subcamps of Kaiserwald in early 1944. Hungarian Jews from Auschwitz-Birkenau and from the Łódź Ghetto were also taken to Kaiserwald in 1944.
In March 1944 there were 11,878 prisoners in the camp nearly all of whom were Jewish. They were used as slave labourers in mines, factories and farms. They suffered from hunger, exhaustion, cold and overcrowding. They worked for the German army.
Dissolution & Liberation
As the Red Army advanced on Riga, all prisoners under 18 and over 30 were murdered. The evacuation took place in late June and July 1944. Apart from some prisoners who reached Stutthof overland via Libau, most were marched to the port of Riga, where they boarded ships bound for Danzig.
Aftermath
The Red Army took over the camp on 15 October 1944 and later used the camp to house Axis prisoners of war.
During the Soviet era, a residential neighbourhood was built on the site. A monument was erected in 2005.