The first of the commemoration services, to be held by the Warilla Sub-Branch on August 4 at the Shellharbour War Memorial, remembers the Declaration of War on August 4, 1914.

The service marks 100 years since Great Britain declared war against Germany and the decision that Australian military would join Britain on the battle field.

Australia, Canada and New Zealand offered their services to Great Britain. Australia sent an expeditionary force of 20,000 men and the Royal Australian Navy.

A total of 416,809 Australian sailors and soldiers enlisted for WWI, and of these there were 215,585 casualties (64.98 per cent).

Warilla RSL Sub-Branch president Kim Kearney said the event was the start of commemoration services taking place Australia-wide over the next four years.

"This will be the very first service to begin the centenary services in Shellharbour," Mr Kearney said.

"On the day, we will have wreath laying, last post and ode at the memorial.

"With the sponsorship of Bendigo Bank we have been able to get the word out."

Upcoming services include the German New Guinea Surrender on September 12, and Emden Sunk Commemoration of the RAN casualties of WWI on November 10, held at the War Memorial in the Caroline Chisholm Park Shellharbour Village at 10.30am.