The Order of the Thistle, the highest order of chivalry in Scotland and a rough counterpart to the Order of the Garter in England, will welcome Prince William as its newest member tomorrow.

The Order of the Thistele was established in 1687 when James II of Scotland and VII of England, who established the order to thank the knights who had heped him unite both kingdoms.

It is the highest honour available in Scotland made up of 16 Knights as well as royal members including the Sovereign of the Order, The Queen, HRH the Princess Royal, HRH Prince Philip, Duke of Edinburgh and HRH Prince Charles, Duke of Rothesay.

On Thursday morning the Knights of the Order of the Thistle will gather in the Signet Library in Edinburgh, dressed in their green velvet mantle, hat and collar where they will wait for The Queen and The Duke of Edinburgh.

In Parliament Square the Band of the Royal Regiment of Scotland will accompany the Guard of Honour found by The Queen's Body Guard for Scotland (Royal Company of Archers) and the Colours of the Royal Company.

Once in the Square the members of the Order will follow The Queen and The Duke of Edinburgh into St Giles’ Cathedral along with the Order’s officers.

At the end of the service the procession will return to the Signet Library before all the Members of the Thistle lunch at the Palace of Holyroodhouse.