Each of the Seven Fathers founded one of the seven Dwarf clans. Durin I was the eldest, and the first of his kind to awake in Middle-earth. He awoke in Mount Gundabad, in the northern Misty Mountains, and founded the clan of Longbeards; they founded the city of Khazad-dûm below the Misty Mountains, and later realms in the Grey Mountains and Erebor (the Lonely Mountain). Two others were laid in sleep in the north of the Ered Luin or Blue Mountains, and they founded the lines of the Broadbeams and the Firebeards. After the end of the First Age, the Dwarves spoken of are almost exclusively of Durin's line.