The Order of the British Empire was formed in 1917 to reward service to the British Empire in the United Kingdom and abroad. Originally having only a civil division, a military division was added in 1918 to acknowledge distinguished military service of a non-combative nature.

The Order has five classes of appointment in each division and a medal of the Order. In descending order, the classes are: Grand Cross (GB); Knights and Dames Commander (KCB and DCB); Commanders (CBE); Officers (OBE); Members (MBE), and Medal (BEM).

Source:
Australian Honours List