Private: Apapa

At the official celebration of King Albert II's 80th bithday in 2014, the name "apapa" was written on the cake.

It's a family tradition to call grandfather "Apapa" and grandmother "Amama" that stems from Albert's mother's side of the family.

The late princess Astrid of Sweden also used these names for her grandparents. The ones to start the tradition were king Christian IX of Denmark (Astrid's greatgrandfather) and his wife, queen Louise. 

Some more photos of this public celebration at BELvue in Brussels...