Fans and protesters line Royal Mile as King and Queen arrive at St Giles' Cathedral for Thistle service

Hundreds of tourists, Royal enthusiasts and anti-monarchy campaigners gathered on the Royal Mile on Wednesday morning to watch members of the Royal Family arrive at St Giles’ Cathedral for a traditional ceremony known as the Thistle service.

The Order of the Thistle is Scotland’s greatest order of chivalry, and membership is considered to be one of the country’s highest honours. It recognises 16 knights, made up of Scots who have held public office or given “distinguished service”, as well as members of the Royal Family.

King Charles and Queen Camilla arriving for the Thistle Service at St Giles' Cathedral as part of the King's visit to Scotland for Holyrood Week | PA

The King is the sovereign of the order and appointments are entirely his personal gift.

The King and Queen, joined by Prince William and Prince Edward, took part in a procession to the chapel from the Signet Library wearing elaborate green velvet robes and white plumed hats.

The Royal Mile was closed from Bank Street to South Bridge, with dozens of police and security guards ushering crowds behind fences lining the street.

The Prince of Wales, King Charles, Queen Camilla and the Duke of Edinburgh during the Thistle Service at St Giles' Cathedral | PA

Many of those watching were tourists who had stumbled across the spectacle while wandering through the city, and who hoped to catch a glimpse of the Royals in all their pomp.

Jennifer Ryder from Victoria in Australia, who is in Scotland on holiday with her friend Donna, said: “We’re excited. We’re Royalists through and through. We’re hoping to get a good line of sight of Charles and Camilla.”

Jennifer Ryder and Donna Coulston from Rutherglen in Australia are on an eight week trip to the UK and France | Iconic Media

Laura Sailer from Chicago, another supporter of Royals, said she admires the clear stance and commitment King Charles has shown towards tackling climate change, and was impressed with his words when he spoke at the US Congress earlier this year.

“I’m here with my husband and my two friends,” she said. “We knew the Royals were in town because we tried to get tickets for Holyrood but it was closed. But we didn’t know there was going to be a parade today.

Laura Sailer (second from right) is visiting Edinburgh with her husband and two friends | Iconic Media

“I’m hoping to see a lot of pomp and circumstance. It’s fun with all the music and the outfits.”

As well as the fans, the annual spectacle also attracts Scots less pleased to see the King and Queen in the capital city.

More than a dozen campaigners, including ex-SNP MP Tommy Sheppard, joined a protest near Old Fishmarket Close organised by Republic, a UK wide campaign group calling for the abolition of the monarchy.

Over a dozen anti-monarchy activists were among the crowds making their opposition to the Royal visit clear | Iconic Media

Protesters waved large, yellow placards with the message “Not My King”, and made their presence known with loud chants as official guests sailed pass in blacked-out vehicles up the Mile.

One protester, Donald Smith, had travelled into Edinburgh from Haddington, bringing with him a large homemade sign saying “I frown on the Crown”.

“We’re trying to get the message over that not everybody thinks there should be a monarchy,” he said. “I think the numbers are fairly evenly split now in the UK, and it should be something there is more debate about.”

Donald Smith was protesting with the anti-monarchy group Republic | Iconic Media

On Tuesday afternoon, activists from Republic revealed a banner with the message ‘Cut the Half Billion Royal Budget' on the hills above the garden party hosted by the King and Queen in the gardens of the Palace of Holyroodhouse.

Wednesday is the second day of Royal Week, which takes place every year in July. The visit officially began on Tuesday with King Charles taking part in the Ceremony of the Keys at his official residence.

Queen Camilla visited the Royal Scottish Academy of Art and toured the exhibition of Chaos and Control, Printmaking in Scotland Now. She also held an audience with JK Rowling, where the pair discussed their love of books and the importance of children reading.