A new exhibition will honour thousands of government employees who volunteered for military service overseas during World War I, and kept the show running at home.

The Sydney exhibition will focus on the 11,000 New South Wales government employees that signed up for military service in the first World War — many of whom gave their lives for the country.

The exhibition tells stories of public service and war service, pieced together through research in the State archives.

But while the Great War drew many young people into far-away conflicts, others fulfilled essential services at home, while government departments were transformed to perform wartime roles.

The exhibition presents stories from NSW railway and harbour workers, teachers, administrators, printers, nurses, clerks, draftsmen, politicians and police — stories of public service and war service, who had their lives turned upside-down (and sometimes taken from them) by the violent international fighting.

The exhibition opens at the State Records office on April 27.