Diler Khan, whose proper name was Jalal Khan, had reputation of being one of the best and bravest generals of the Mughal emperor Aurangzeb Alamgir. Bhimsen Saxena (a Hindu soldier who served under Aurangzeb) praise his military talents as follow:-
“Dilir Khan Afghan, the holder of the punj-hazari rank, surpassed and excelled all the contemporary nobles in the arts of his swordsmanship and leadership. He knew the tactics and techniques and the rules of discipline and order of warfare very well. Wherever he went, he was greeted by success and victory. ” 
Mughals distrusted the Pashtuns and very few of them were given the rank of 5,000. Niccolao Manucci remarks, “It is a rule in the Mughal empire not to trust the race of Pathans” . Aurangzeb elevated Diler Khan to 5,000 in acknowledgement of his services against Shivaji. But Diler Khan had a chequered military and political career and he suddenly died in 1683 under mysterious circumstances.
Diler Khan belonged to the Baqalzai (or Baqarzai) branch of the Daudzai tribe of Peshawar valley. His father Daya Khan hailed from village Barbar (in the present-day Peshawar district) and was a horse trader . Barbar is situated at a distance of about six miles to the north of Peshawar City and is attached to the Mathra Police Station. 
Darya Khan (Diler Khan’s father) was introduced at the court of emperor Jahangir by Khan-i-Jahan Lodi and on his recommendation the emperor granted him the rank of 3000 Zat and 3000 Sawar. Darya Khan joined Khan Jahan Lodi in his rebellion and was killed in a fight in 1630. His sons Bahadur Khan and Jalal Khan (Diler Khan) also entered into the Mughal service.
Shahjahanpur was founded by Diler Khan in 1647 as a deputy of his brother Bahadur Khan. Bahadur Khan who was campaigning in Balkh at that time, persuaded the Pashtuns of the Roh to migrate to Shahjahanpur district. Soon it became a strong Pashtun settlement .
The town of Shahabad in Hardoi district was founded by Diler Khan in 1677.
|Portrait of Daler Khan (a Daudzai Pashtun), a noble of emperor Aurangzeb, c.1686. By an anonymous artist. Source|
|Portrait of Nawab Daler Khan Daudzai (Pashtun). Source|
1- “English translation of Tarikh-i-dilkasha (Memoirs of Bhimsen relating to Aurangzib’s Deccan campaigns”, p-141
2- “Storia Da Mogur”, Vol-II, p-241
3- “Nama-i-Muzaffari”, by Muhammad Muzaffar Hussain, p-7
4- “On a Foreign Approach to Khushhal”, Dost Muhammad Khan Kamil, p-14
5- “The Afghan nobility and the Mughals”, Rita Joshi, p-128