The 82-year-old monarch took a carriage ride through Copenhagen and attended a ceremony at city hall.
The two events had been postponed following the death in September of Britain’s Queen Elizabeth II, her third cousin.
Now Europe’s only reigning queen, Margrethe waved from the city hall balcony, greeting a crowd of about 1,500 people in the capital’s main square.
At the end of September, the queen stripped four of her grandchildren of their titles, sparking unprecedented royal drama and leading her enraged second son Prince Joachim to air the family’s dirty laundry in public.
The queen announced that 53-year-old Prince Joachim’s four children would no longer be able to use the title of prince or princess after January 1st.
She apologised for the hurt caused but said the move was to allow her grandchildren to live normal lives without royal obligations.
Prince Joachim and his wife, Princess Marie, saw this as a slap in the face and vented their bitterness to the press.
Both were present for the jubilee, however, and the celebrations have been seen as an opportunity to close a difficult chapter – at least in appearance.
Pensioner Margit Lauritze, a well-wisher among those gathered in the capital, told AFP: “Family is very important for our queen, and I think it is very important for the princes that the family is reunited.”
“In all families, there are differences, and they will find a solution, I’m sure”.