Mohsin Zadeh 'Abdullah, by whom one of these mashqs is attributed to Sheikh Hamdullah was the grandson of Damad Mahmud Pasha, born in Istanbul in 1832. He was among the most sucessful students of Kadiasker Mustafa Izzet Efendi and is celebrated, along with Shefik Efendi, as having been one of his leading successors. He became one of the scribes to the office of the Grand-Vizier. He was honoured with the title Reisü'l Hattatin (Head of Calligraphers) and died in 1894 (Sevket Rado, Türk Hattatlari, Istanbul, 1980, p. 231).
For a note on Sheikh Hamdullah see lot 99.