Mühendislikhane-i Berrî-i Hümâyûn (مهندسخانۂ برئ همايون; 1795 - 1883) was a military school in Istanbul that trained artillery officers, engineers, and cartographers for the Ottoman military. Established by Selim III (r. 1789 - 1807), in part through the advice of Istanbul-born Armenian Ignatius Mouradgea d'Ohsson (1740 - 1807), who served as a Swedish diplomat to the Sublime Porte, the school was meant to resemble the most advanced European military academies of the time, with an emphasis on mathematics and engineering. When Selim III was deposed by Janissaries in 1807, the school suffered as a result since it threatened the historical privileged military and social role of the Janissaries. When the Janissaries were abolished in 1826, the school had to rebuild nearly from scratch, though it benefitted from a wider zeitgeist of reform, particularly during the Tanzimat era in the mid-19th century.