Middlesbrough was of vital importance to Britain's war effort. The town, and its surrounding area, contained a number of vital industries including shipbuilding, chemicals, iron, steel and other metals, and engineering, as well as a joinery firm that played a leading role in the wartime aviation industry. The ICI plant at nearby Billingham also played a leading role in the creation of petrochemicals and explosives.

As with many communities, the start of the war saw Middlesbrough faced with hastily having to bring its Air Raid Precautions and civil defence services up to full strength. With its strategic importance it was believed that Middlesbrough would be an obvious target for the Luftwaffe. As a result, schoolchildren and other vulnerable people were evacuated from the town at the very start of the war in a scheme that did not prove entirely successful.

Middlesbrough became the first built-up urban area in mainland Britain to be bombed. In the event, Middlesbrough was raided periodically throughout the war with the worst coming on the night of 25/26 July 1942, when waves of Luftwaffe bombers dropped almost 30 tons of bombs on the town. The raid killed sixteen people and caused very extensive property damage. Meanwhile, just days later, bombs fell on the town's railway station as a train was waiting at the platform there. The pictures of the resulting damage were wired around the world.