After a 52-year reign, Queen Margrethe II of Denmark is bowing out.

The monarch, 83, officially stepped down from the throne Jan. 14—handing over duties to her eldest son Crown Prince Frederik, now King Frederik the 10th. 

The abdication is Denmark's first in nearly 900 years, with the last event of its kind being in 1146 when King Erik relinquished his role to enter a monastery. 

Traditionally, the succession to the Danish throne has taken place following the death of a sovereign. But this time, it occurred when Margrethe—who will still be referred to as queen—signed a declaration of her abdication during a meeting of the Council of State at Christiansborg Palace in Copenhagen.

The king then became the new sovereign, and his wife took on the title of Queen Mary. (She was previously Mary, Crown Princess of Denmark.) Their 18-year-old son Prince Christian is now the new Crown Prince and heir to the throne. Next in line is his sister Princess Isabella, 16, followed by their 13-year-old brother Prince Vincent and his twin sister Princess Josephine.