Darwin bore the brunt of these devastating attacks which began on 19 February 1942. The first two Japanese air raids against Darwin, and the events which followed, represent the most humiliating moments in Australia's military history. The Allied command had failed to appreciate the significance of the Japanese buildup to the north-west of Darwin, despite the pattern of recent events at Pearl Harbor, Singapore and Rabaul. The port was without fighter defences and the army garrison consisted of just two brigades. Darwin harbour had become choked with vulnerable naval and merchant vessels, defended by an anti-aircraft battery of only eighteen guns.