Primary Arabic sources tell us that around 638, a severe plague broke out in ‘Amwās, the ancient Emmaus in Syria, resulting in massive fatalities among the soldiers of the Arab army.

A slave boy of Byzantine origin, who had grown up to become a scientific scion of Archimedes in the annals of world intellectual history, was offered a hefty sum of 1,000 dinars as a gift from his royal Seljuq patron Sultan Sanjar ibn Malikshāh in Khurāsān (r. 1097–1157).