Owing to the events of WWII and the advance of the Red Army of the Soviet Union, the Hungarian Coronation Mantle was taken for safekeeping to Pannonhalma in November 1944, and the other coronation insignia to Veszprém. On 5 December, the insignia were transported to Kőszeg, behind the newly built defence line.

Historians are uncertain about the whereabouts of the insignia after they were taken to Kőszeg.
It is likely that they were first kept in the Dominican school, then they were moved on 27 December 1944 to the village of Velem where a bunker was built to conceal them. The Coronation Mantle may also have been taken to the same spot on this date. As the Russian front was further advancing, the containers were taken to Kőszeg on 18 March 1945 and placed in an air defence bunker, built for this specific purpose, at the foot of Calvary Hill. The members of the Crown Guard were accommodated in the adjacent building.

On 26 March, a decision was adopted to move the insignia once again. The commander of the Crown Guard, Colonel Pajtás, and a handful of his most trusted men put the Holy Crown and the insignia on board of a lorry, and they left the country at Rattersdorf. When they were captured by the Americans, they told them where they had hidden the insignia. The American army kept the precious items in Germany for a while and transported them to the US, to Fort Knox, until they were returned to Hungary in 1978.

Following WWII, the crown guard bunker in Kőszeg decayed gradually. In 1992, a plaque was placed on the wall of the bunker; in 2012 Kőszeg municipality had it renovated and turned it into an exhibition space.