[Kuruharan]

Mount Gundabad was the awakening site of Durin. (Gundabad itself is a Dwarvish word, not orcish.)

After he awoke he wandered the world for a couple of decades and when he returned to Gundabad he found the other Dwarf Fathers there waiting for him. Gundabad was where the Dwarves first established themselves. It was their first capital.

When the different houses of the Dwarves dispersed Gundabad remained in the hands of the Longbeards, even though many of them went south to Khazad-dum. However, Gundabad was so depopulated that it may have been seized at the end of the First Age by fugitives from Thangorodrim. Soon afterward Gundabad may have been retaken by the Longbeards in alliance with the Edainic Men of Wilderland.

During the Dark Years the orcs overran the northern mountains again and Gundabad was lost for (possibly) the second time. It may have been retaken with the end of the Dark Years.

It might possibly have been Dwarves of Gundabad that killed Fram, lord of the Eotheod, possibly.

It seems likely that the final fall of Gundabad came around TA 1300 (or after) with the establishment of Angmar. After the fall of Angmar it remained in the hands of the orcs of that area.

It should be noted that much of this post is purely speculative in nature. The information is gleaned from tidbits of information from all over the place. One of the more important sources is "Of Dwarves and Men" in The Peoples of Middle Earth.

This is probably more than you ever wanted to know about the (theoretical) history of Gundabad.