Norway's King Harald has honoured a penguin with a knighthood. The honour - which was approved by the king - was bestowed on the three-foot tall king penguin named Nils Olav was at a secret ceremony at the animal's Edinburgh Zoo home. The ceremony - which was known only to 71-year-old Harald and his advisers - saw the penguin waddle out in front of 130 Royal Guardsmen on parade before being dubbed on the shoulders and having a medal attached to his wing to confirm the knighthood. Despite being unable to attend the ceremony, Harald sent a message of congratulations, calling the penguin "our trusty and well-beloved" Nils, and saying he is "in every way qualified to receive the honour and dignity of knighthood". Nils is the mascot of the Norwegian's King's Guard, and a successor to the first penguin adopted by the guards more than 30 years ago. In 1972, a young lieutenant of the Norwegian Royal Guard visited the zoo and adopted a king penguin as a mascot, bestowing on him the rank of Lance Corporal. He was named Nils Olav after a soldier, Nils Egelien, and Norway's then King Olav. Since then the penguin - and his current successor - has risen through the ranks of Corporal, Sergeant, Regimental Sergeant-Major, Honourable Sergeant Major and, in 2005, Honorary Colonel-in-Chief, before now being made a knight. According to zoo staff, Nils Olav always recognises the guards when they visit. Darren McGarry, the zoo's animal collection manager, said:"Nils always recognises the Norwegian Guardsmen when they come to visit him. "They came in recently and he immediately walked towards the gate. He loves the attention he receives at the ceremony and even takes time to inspect the troops." Norway gave the zoo its first king penguin when it opened in 1913.