Not a lot is known of this dwarf's origin, as the earliest memory he has is of rangers of the north and their camp, where he woke one day. Indeed he lost his memory and all that the rangers could tell him was that they found him fighting trolls near trollshaws. They went to help him but were too late. One of the trolls landed a hit on the dwarf's head which must have been the cause of his loss of memory, but not, fortunately, his life. Apart from that, the dwarf had an anonymus letter on him in which he was told to go to ered luin to assisst his kinsmen in battle against the goblins. Fortunately, the letter countained the dwarf's name - Diringul - and the seal was that of Erebor, the Lonely mountain. After regaining what knowledge he could, and after his wounds were healed, he set off to the Blue Mountains as the letter instructed him. Before he departed, he offered to one day repay the Dunedain for their rescue, however they would have none of it and so, he decided to help others in the same manner - never to ask for payment or expect any in return for his services. 
With his newfound strength and life, Diringul set off to fulfill his task, but once he got to his goal, he quickly realized that the dwarves of the Blue Mountains had more than just goblins to deal with.