Can anyone tell me if this is WW1 or WWII and what is the significance of it please. It has what looks like 99t on the back. What is that for.
The 'Rising Sun Badge' was worn on the hats of soldiers in the Australian Army during both World Wars. This design is an example of the 'Third Pattern' badge, with the 13 point rising sun, which was used from May 1904 until 1949. The design changes of the Rising Sun badge can be seen on the Wikipedia page.
The enamelling and colour suggests that may have been worn by an officer.