Hadean
The Hadean () is a geologic eon of the Earth pre-dating the Archean. It began with the formation of the Earth about 4.6 billion years ago and ended, as defined by the ICS, 4 billion years ago. , the ICS describes its status as ""informal"". Geologist Preston Cloud coined the term in 1972, originally to label the period before the earliest-known rocks on Earth. W. Brian Harland later coined an almost synonymous term, the "Priscoan period", from "priscus", the Latin word for "ancient". Other, older texts simply refer to the eon as the Pre-Archean.
Jewish diaspora
After the Persian conquest of Babylon in 539 BCE Judah (Hebrew: יְהוּדָה Yehuda) became a province of the Persian empire. This status continued into the following Hellenistic period, when Yehud became a disputed province of Ptolemaic Egypt and Seleucid Syria. In the early part of the 2nd century BCE, a revolt against the Seleucids led to the establishment of an independent Jewish kingdom under the Hasmonean dynasty. The Hasmoneans adopted a deliberate policy of imitating and reconstituting the Davidic kingdom, and as part of this forcibly converted to Judaism their neighbours in the Land of Israel. The conversions included Nabateans (Zabadeans) and Itureans, the peoples of the former Philistine cities, the Moabites, Ammonites and Edomites. Attempts were also made to incorporate the Samaritans, following takeover of Samaria. The success of mass-conversions is however questionable, as most groups retained their tribal separations and mostly turned Hellenistic or Christian, with Edomites perhaps being the only exception to merge into the Jewish society under Herodian dynasty and in the following period of Jewish-Roman Wars. While there are some references to maintaining the tribal separation among Israelites during the Hasmonean period, the dominant position of the tribe of Judah as well as nationalistic policies of Hasmoneans to refer to residents of Hasmonean Judea as Jews practically erased the tribal distinction, with the exception of the priestly orders of Levites and Kohanim (tribe of Levi).