Early counterweight trebuchet

Timeline

1. 1171–1173Syria–Anatolia frontier · SyriaFrom the first half of the 12th century, Arabic, Syrian, and Byzantine sources began using new terms for larger, heavier stone-throwing engines; scholars believe this reflects an emerging power innovation replacing human traction with counterweights, though descriptions of specific mechanisms in documents of the early 1170s remain vague.
2. 1174–1177Levant · LevantWhen the Sicilian army besieged Alexandria in 1174 it already carried various siege engines and imported black stone balls; both Frankish and Ayyubid sides deployed large trebuchets at sieges such as Jacob's Ford (1179). Scholars such as Michael Fulton note that the destructive power of engines against stone walls was still limited in this period, but trends toward prefabricated components and dedicated ammunition transport were already visible.
3. 1178–1180Both sides of the Mediterranean (the Muslim world and Latin Europe) · MediterraneanBy around 1180, knowledge of counterweight trebuchet technology spread to Eastern and Western Europe through the Crusades and Sicilian–Byzantine contacts; the early type depicted in al-Tarsusi's manuscript of about 1187 was still fairly primitive, indicating that technology at the end of this decade was still in an early stage of evolution and had not yet produced the systematic impact on castle design seen in the 13th century.