Around 100,000 are expected to descend on Scarva in Co Down for the annual Sham Fight between King William and King James on July 13.
The battle re-enactment, preceded by a large-scale parade by the Royal Black Institution - hosted by Sir Knight Alfred Buller Memorial RBP 1000 - is now firmly established as a major tourist and family attraction.
Sovereign Grand Master of the Royal Black Institution, Rev William Anderson, said: "The Sham Fight is a truly wonderful family occasion and we are looking forward to another extremely successful day.
"As a Christian-based organisation, the religious service is extremely important to our members.
"The procession to the field, through thousands of people lining the village streets, is a unique spectacle of music and pageantry. And the actual re-enactment of the famous battle always attracts attention. The Thirteenth, as it is so often and fondly described, is about history coming alive and is to be enjoyed by everyone."
Rev Anderson paid tribute to the organising committee of volunteers and RBP 1000, which celebrates its centenary this year.
To mark the occasion, members will be given the honour of leading the main parade, accompanied by Sir Henry Inglesby Fife and Drum.
King William is played by John Adair and King James by Colin Cairns. The main protagonists are accompanied by re-enactors in period costume and a number of horses. Both kings will be dressed in new Williamite uniforms this year.
An adjoining cultural field will also showcase musical entertainment, highland dancing, historical displays, and other activities for the many visitors to enjoy throughout the day.
The Sham Fight will take place at 1.30pm, prior to the religious service at 2pm, and will be preceded by the parade, which will start at 11.15am, with up to 90 preceptories and as many bands taking part in the procession through Scarva.
Approximately 4,000 members of the Royal Black Institution will be participating in the event, accompanied by a wide selection of music, including flute, pipe, accordion and brass bands.