Twenty-three sarcophagi are located in the Tomb of Kings. All of them underwent the hero's journey and therefor deserve to be there. Twenty-three blades shimmer in the torchlight. But do not dare to take them, or you will perish. -- Kirboldir, A. Razortongue
When King Ugum Highboot lead his people to what later became Kirboldir, his twenty most loyal warriors perished to a black dragon inhabiting the area. Upon defeating the creature, Ugum ordered a tomb to be build for these brave souls and for all of those who would come later: the tomb of kings. The burial rite itself is now known as the Hero's Journey and every Hill Dwarf that dies giving his life for the city will be placed into the tomb and will undergo this ritual. However, since Kirboldir knew a relatively peaceful time until its destruction, none are buried there expect for the kings and the first twenty warriors.
Before the ritual can commence, a sarcophagus with the name and a etching of the deceased greatest deeds is placed in the tomb of kings. While this construction is going on, the body is getting prepared: oils are applied to preserve the body. On the day of the ritual, the deceased receives his final feast: outside of the tomb a party is organised, with lots of drinking. At the end of the party, a keg of ale is emptied into the throat of the deceased: a final drink for they who passed away. After this, the body is brought to the sarcophagus and buried. The weapon of the deceased is then placed on top of the sarcophagus to seal it off.