Duriba fi zaman al-abd al-rafi rahmat allah muhammad bin // al-sultan al-sa'id al-shahid tughluq shah, fi saneh arba'in wa deb miat. 18mm, 8.95 grams. NM (Delhi?), dated (with the date written out) to 749 AH (1348 AD). Goron/Goenka #D370.

This is a rare type with the word "bin" placed below "Muhammad" on obverse. 

Muhammad bin Tughluq was born to Ghiyas-ud-din Tughlaq, who was in turn the son of a Turkic slave father and a Hindu Indian mother, and was the founder of the Tughluq dynasty after taking control of the Delhi Sultanate. He saw a long and eventful reign - numismatically, he left a fascinating record which included numerous coin types which included remarkable issues of fiduciary bronze tankas and half-tankas.