 The British appointed Raja Bilah "penghulu" of Blanja while his son Raja Yacob became "penghulu" of Tronoh, which generated large revenues after the opening of the Tronoh Mines, the largest tin producer in the world in the 1920s.Mandailing is the name of region Luat Mandailing, which is now almost in Mandailing Natal Regency in North Sumatra.The first group who came to this region were the Lubis and Nasution, later followed by the Siregar, Harahap and so forth.