The Hegira is the journey or migration of Muhammad (the Islamic prophet) and his followers from Mecca to Yathrib in 622. After getting a warning from a group he and his followers surreptitiously left his residence in Mecca to migrate to Yathrib which was 320 km north of Mecca. In his migration, he was followed by Abu Bakr who later became one of the Caliphs.
Political machines started as grass roots organizations to gain the patronage needed to win the modern election. Having strong patronage, these "clubs" were the main driving force in gaining and getting out the "straight party vote" in the election districts.
Byzantium/Constantinople was conquered in 1451, but the empire continued to decline starting around the 18th or 19th centuries. It officially died in WWI. As for how long it was a major threat to Europe, the empire's prime was the 16th century, under Suleiman the Magnificent.
An executive order is not passed by Congress
