Queen Camilla and the Duke of Edinburgh are set to receive a major honour from King Charles today, as members of the Royal Family have started arriving at St Giles’ Cathedral in Edinburgh for the Order of the Thistle service.

The Queen and Edward will shortly become members of Order of the Thistle – Scotland’s greatest order of chivalry on Day two of Holyrood week.

Each year the monarch traditionally spends a week based at the Palace of Holyroodhouse in Edinburgh, known as Holyrood Week or Royal Week. This year events have been scaled down due to Thursday’s General Election.

In a private ceremony today, Camilla and Edward, who were appointed Royal Knights of the Order by the King, will be formally installed as members of the Order.

Also being appointed to the Order will be forensic anthropologist Baroness Sue Black, lawyer Baroness Helena Kennedy and Scotland’s first black professor Sir Geoff Palmer.

The King and Queen have arrived at St Giles Cathedral and will shortly receive a royal salute from the Guard of Honour, while the Band will the National Anthem.

Charles and Camilla were greeted by the Interim Moderator of St Giles’ Cathedral, the Chancellor of the Order of the Thistle, the Dean of the Order of the Thistle, and the Secretary of the Order of the Thistle.

The Prince of Wales, known as the Duke of Rothesay in Scotland, is also attendance at today’s ceremony.

Charles is the sovereign of the Order and appointments are his personal gift made independently of Downing Street to those who have public office or have contributed significantly to national life.

Camilla is patron of Maggie’s Cancer Care Centres, founded in Edinburgh in 1996, while she is also patron or president of a number of charities based in Scotland and is an honorary member of the local Ballater Women’s Institute and the Upper Deeside Art Society.

Edward holds several patronages of Scottish charitable organisations including the Edinburgh International Festival.

During the day the couple will attend an event marking the start of celebrations commemorating the 900th anniversary of the Edinburgh Castle.

The very best of the city will be on display with performances from Dance Base, Scotland’s National Centre for Dance, author Sir Alexander McCall Smith will perform a short poem and the King and Queen will speak to local Edinburgh organisations at various displays, showcasing innovation, food, design, and charity.