The Luftwaffe's bombing raid on the harbour of Bari occurred during the Allied campaign in Italy. Bari was a vital shipping port used to support the Allied forces, as it served as a logistics hub for both troops and supplies. On December 2, aerial assaults commenced when German bombers targeted this strategic location, resulting in extensive damage and chaos in the harbour. The raid was swift and brutal, with several ships being sunk, leading to not just loss of cargo but also taking lives of military personnel and civilians who were present in the vicinity.

Among the ships sunk was the American cargo vessel SS John Harvey, which unknowingly was transporting a large stockpile of mustard gas. The subsequent sinking of the ship led to the release of this toxic chemical into the waters of Bari, resulting in one of the largest instances of chemical exposure for Allied forces. Immediately after the explosion, hundreds of soldiers began to suffer from symptoms of gas poisoning, creating a medical emergency that would challenge the capabilities of military hospitals.

The event took place amidst the broader context of World War II and reflected the ruthless tactics employed by both sides during the conflict. With no prior acknowledgement of chemical warfare in this theatre, the incident raised alarms among military and political leaders regarding the potential use of poison gas. The attack not only had a significant military outcome but also influenced subsequent strategies, operational planning regarding chemical weapons, and public perceptions of war conduct.