The birthday of Princess Ingrid Alexandra of Norway is observed in Norway every January 21. This day is significant as it is an official flag flying day, meaning that all state agencies and branches of government are required to display the national flag. Princess Ingrid Alexandra, born on January 21, 2004, is the elder child of Crown Prince Haakon and Crown Princess Mette-Marit and is second in line to the Norwegian throne. She has a younger brother, Prince Sverre Magnus, and an older maternal half-brother, Marius Borg Høiby. The introduction of absolute primogeniture in 1990 ensures that Ingrid Alexandra retains her status as the heir regardless of her brother's birth. This makes her expected to become the first female monarch in Norway since Queen Margaret I of Denmark.