Used by the Ottoman empire during the fall of Constantinople.
When the army assembled at the city walls of Constantinople on 2 April 1453 CE, the Byzantines got their first glimpse of Mehmed's cannons. The largest was 9 metres long with a gaping mouth one metre across. Already tested, it could fire a ball weighing 500 kilos over 1.5 km. So mammoth was this cannon that it took an awfully long time to load and cool it so that it could only be fired seven times a day.
