The highest honour English subjects can receive from their Queen is the Order of the Garter. Across the border in Scotland, however, exemplary service is rewarded with membership of the 11th-century Order of the Thistle. And this week Queen Elizabeth donned the order's dramatic emerald velvet robes and egret-plume hat to welcome two new members into the group of knights.
Like the monarch, the Duke of Edinburgh was dressed in a green, white silk-lined gown, outsize gold and silver tassels and the order's badge, for the ceremony in the chivalric brotherhood's chapel at Edinbugh's St Giles Cathedral.
In line with the Order's original medieval roots - it later fell into disuse but was revived in the 17th century by James II - the royal couple were welcomed by a fanfare from the Household Trumpeters. Accompanied by the Princess Royal, and a green-clad page, they then proceeded through the cathedral into the Thistle Chapel where the historic ceremony was being held.
The recipents of the Order - who take for their motto the words 'Nemo me impune lacessit' - No one provokes me with impunity - were senior retired judge Lord Cullen, and East Lothian Lord Lieutenant Sir Garth Morrison.