The SS Biarritz was used to transport the 2nd Battalion of the Welsh Guards to Boulogne. At 1130 hours on the 21st May 1940, they were ordered to pack and prepare to be sent to Dover, where they embarked that evening, arriving at Boulogne on the morning of 22nd May. The 2nd Welsh Guards were tasked with defending Boulogne and by the evening of the 22nd, they had already prepared their defences and first saw action on the morning of the 23rd May. Their resistance continued until late afternoon when they were ordered to retreat to the area of the docks, from where they were evacuated.