The royal dwarven gravestone is a 3 minute gravestone requiring the King of the Dwarves quest. It is available from Blasidar the sculptor in Keldagrim for 500,000 coins. It is the longest-lasting gravestone in the game, followed by the equally priced Angel of Death which lasts only 2:45 minutes.
Trivia[]
During the 2011 Hallowe'en event, an advertised Royal Dwarven Gravestone read "The only way to meet a dwarf taller than you! You know, because they're short and stuff."
Prior to the death rework, the royal dwarven gravestone would last for 15 minutes.