​​Shortly after the war began, on 12 May 1940 the first air raid on Aachen took place. By the time the fighting for Aachen began on 12 September 1944, (with the crossing of the western border and the attack on the Westwall on 15 September), a total of 2,364 people had been killed in 64 smaller and five large attacks. In addition, the city itself was also severely damaged.

After more than five weeks of fighting in the city, some of which was fought from street to street with tanks and artillery, 43% of the city's approximately 14,000 houses were completely destroyed, and another 40% damaged. Of Aachen‘s 68 churches and chapels, 25 were destroyed and 43 others severely damaged. The historic town hall was also in ruins, as the last medieval residential buildings had fallen victim to the destruction. Although Aachen Cathedral had been badly damaged by bombing, its basic substance had been preserved.

For the buildings in Annastrasse, the destruction of the Annakirche, Aachen's oldest Protestant church, was particularly well documented. The church burnt out in a bombing raid on 14 July 1943, and in April 1944 the pastor's house and parish hall were hit. However, the greatest destruction in Annastrasse, to which the south wall and tower of the church also fell victim, was the result of artillery fire during the Battle of Aachen.

​Reconstruction of the city began as early as November 1944. The first priority was to rebuild housing, initially on a makeshift basis, as up to 5,000 people a week returned to the city very soon after Aachen's surrender. Discussions about the goals and implementation of reconstruction, especially the treatment of architectural monuments, continued into the 1980s. By then, most of the destruction of the war had been erased from the cityscape. However, where no new buildings were erected and areas were instead used as, for example, car parks, the remains and imprints of destroyed buildings can still be seen today.​