The Prince of Wales and Duchess of Cornwall will join Scotland's First Minister, veterans and serving soldiers at a service to remember the thousands who lost their lives in one of the biggest battles of the First World War.
An estimated 21,000 British soldiers died in the Battle of Loos in 1915, about 7,000 of whom were Scottish.
Dundee was one of the worst areas affected, with a large number of the casualties coming from the 4th Black Watch based in the city.
Charles, Royal Colonel of the 3rd Battalion (The Black Watch), The Royal Regiment of Scotland, will attend a service with his wife and First Minister Nicola Sturgeon in Dundee to pay their respects to those who died.
Charles' great uncle, Captain Fergus Bowes-Lyon, died on the third day of fighting.
Events to mark the centenary of the battle started yesterday with the lighting of a beacon at dawn at the top of Dundee war memorial.
Today's service is due to start with a parade of about 250 current service personnel and 300 veterans.
The City Square will then be transformed into a "cathedral", with four ministers from Dundee representing the Scottish Episcopal, Roman Catholic Church of Scotland, Church of Scotland and the Chaplain General to the Armed Forces.
Charles, known as the Duke of Rothesay when in Scotland, will lay a wreath against a specially-commissioned memorial stone along with the First Minister and Lord Provost of Dundee.
Ms Sturgeon said: "With around 30,000 Scots serving at Loos, its effect was felt throughout every village and town in Scotland.
"The weekend of national commemorations will be a fitting tribute to those that fought, those that died and those that were left at home."
Lord Provost Bob Duncan said: "The battle affected every Scottish regiment and was also Dundee's darkest hour.
"The terrible losses, particularly among local Black Watch battalions, had a profound effect on the city.
"This weekend presents an opportunity to remember their heroic sacrifice and to honour their memory."
Charles and Camilla will later attend a reception for forces personnel and veterans and view an exhibition on the Battle of Loos by pupils from Dundee schools.