April 16 is the birthday of Queen Margrethe the Second, born in 1940 and queen since 1972. On Margrethe's birthday, she appears on the balcony of her residence in Amalienborg with the closest family, and receive the cheers of her subjects.
Queen Margrethe's full name is Margrethe Alexandrine Þórhildur Ingrid, and she is the oldest daughter of King Frederik IX and Queen Ingrid. In 1967 she wed Henri count de Laborde de Monpezat from France, and in 1968 she had her first son, the heir to the throne, Frederik.
The year after - in 1969 - Margrethe had her second son, Joachim, and three years later, when King Frederik died, she succeded him on the throne of Denmark. Due to the last change of the Danish constitution (Grundloven), it became possible for the oldest child of the ruler, regardless of sex, to inherit the throne, a law many consider proposed and passed primarily in order to let Margrethe inherit the throne.
At 12 o'clock, after the change of the guard, the doors of the palais in which Margrethe lives is opened, and Queen Margrethe and her closest family step out onto the balcony, and are greeted with loud cheers. After a while, they move back into the palais, and the also traditional call from the crowd "Margrethe, Margrethe, kom nu frem, ellers går vi aldrig hjem" (Margrethe, Margrethe, come on out, or we will never go home), usually makes the royal family appear two or three times more.
The Queen's birthday is one of the few times a year at which you can watch the Royal Guard in their celebratory attire, the red jacket and bright blue trousers. The Royal Guard Music Corps adds to the generally good mood of the situation by playing birthday songs and other joyful music.
Also a part of the celebrations is the parade in front of two of the palais' of Amalienborg, which can also be seen every day of the year at noon, although in the normal attire of the Royal Guard. Still, the bright colors of the celebratory uniform really helps to underline the importance of the day to all Danes.