Denmark's new King Frederik X has formally taken the throne following his mother Margarethe II's recent surprise abdication announcement after 52 years as monarch.

Prime Minister Mette Frederiksen has proclaimed Frederik X the new King of Danemark on the balcony of Christiansborg Palace on Sunday, after Queen Margrethe II gave up the throne. 

More than 100,000 people turned out for the unprecedented event in the Danish capital Copenhagen. 

The Queen finalized and signed her abdication, which was first announced in her New Year’s Eve address, at a meeting with the Danish Cabinet.

After signing it, left the room with tears in her eyes, saying: "God bless the king."

Her 55-year-old son, Crown Prince Frederik, was then proclaimed King Frederik X  at the Christiansborg Palace.

The 83-year-old Margrethe is the first Danish monarch to voluntarily step down in almost 900 years. She has reigned in the small Scandinavian country for exactly 52 years, taking the crown on January 14, 1972.