Firishta's History (Gulshan-i Ibrāhīmī) 6.8.3

6.8.3

The King after this victory returned in triumph to Ghizny, and in the year 418 removed the governor of Toos (Abool Hurb Arslan) to the government of the district of Badwird, in order to chastise the Suljook Toorkmans, who, having crossed the river Amoo, had invaded that province. The General, however, being defeated in several engagements, wrote to the King, that without his own presence nothing could be done against the enemy. Mahmood put his army in motion, and having come up with the Suljooks, gave them a total defeat. At this time, also, his generals having conquered Eerak, he himself marched in that direction, and secured all the treasure that had been amassed by the race of Boeia. Having then introduced some new laws respecting the religion of the inhabitants who had adopted false tenets, he conferred the government of Rye and Isfahan on his son, the Prince Musaood, and returned to Ghizny.