Durin the Deathless, one of the seven Fathers of Dwarves, justly got his name: he had lived an exceptionally long life, longer than any other dwarf.
The Fathers of the Dwarves, as they were later called, created Valar Aule in the Age of Trees, and later put to sleep the seven dwarves in the numerous mountains of Middle-earth (Ennorath). In holy solitude, Durin the Deathless was put to sleep under the Mount Gundabad, in the north of the Misty Mountains, and after that, it was his resting place that became sacred to all generations of dwarves.
Durin awoke some time after the awakening of the Eldest Children of Ilúvatar in 1050 in the Age of Trees. Waking up and wondering what he would do in the world, he traveled for a long time through Middle-earth and the land of dwarves, gathering like-minded people.
The oldest dwarf, along with other dwarfs, came to the lake of Mirrormere, located in the valley below Caradhras in the Misty Mountains. He founded Khazad-Dum – a huge underground city, the richest and greatest of the Dwarven Palaces. Later, Khazad-Dum was renamed Moria (in Sindarin (one of the Elvish languages) it means “black abyss”).