Question

Which of these events resulted in further Crusades one hundred years after the First Crusade?

In 732, Muslims invaded the Frankish Kingdom.
In 1093, Muslim Turks attempted to conquer Byzantine.
In 1187, Muslim forces retook the city of Jerusalem.
In the 1200s, Mongol invaders reached Muslim lands.

Answer 1

In 1187, when Muslim forces (Saladin) retook Jerusalem. That loss prompted the Third Crusade (1189–1192), roughly a century after the First Crusade (1096–1099). The other events either came earlier (732), helped trigger the First Crusade (late 11th‑century Turkish pressure on Byzantium), or did not produce a comparable Crusade response (Mongol incursions).