King Harald and Queen Sonja of Norway arrived in the UK on Tuesday for a three-day visit to mark 100 years of their country's independence from Sweden.
The Norwegian royal family sailed up the Thames on the royal yacht Norge, owned by the king and manned by the Royal Norwegian Navy.
A visit to Downing Street involved greeting Prime Minister Tony Blair and his wife Cherie.
Crown Prince Haakon and his heavily pregnant wife, Crown Princess Mette-Marit, are accompanying the king and queen.
The king of Norway, the Duke of Edinburgh and the Queen viewed Norwegian items from the Royal Collection.
The Duchess of Cornwall attended a state banquet at Buckingham Palace on the first night of the royal visit.
The occasion marked the first time the Duchess of Cornwall had worn a royal tiara. Her dress was designed by Robinson Valentine, the makers of her wedding dress.