Following training, the brigade was dispatched to the Middle East, departing from Melbourne in May 1940. However, while they were at sea they were diverted to the United Kingdom in order to help defend the island against a possible invasion by German forces following the Fall of France. After landing at Gourock, Scotland, the brigade moved south to Salisbury Plain where they undertook training and defensive duties. In the United Kingdom, the 18th Brigade provided a cadre to the newly formed 25th Brigade and became part of the 9th Division when it was raised in October 1940.