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.
Hauran
By the early 2nd century CE, the last vassal kings of the Hauran region, Agrippa II (r. 53–100 CE) of the Herodian Tetrarchy and Rabbel II (r. 70–106 CE) of the Nabatean Kingdom had died and Rome under Emperor Trajan (r. 98–117) no longer saw the need for local intermediaries. The deaths of the Herodian and Nabatean monarchs in relatively quick succession provided an opportunity for the Romans to absorb their domains. Thus by 106, the empire formally annexed the entire Hauran, incorporating its southern part in Arabia Province and its northern part in Syria Province. The provincial boundary apparently followed the boundary just north of the Adraa–Bosra–Salkhad line that had separated the Herodian and Nabatean kingdoms. This administrative division remained for much of the 2nd century. This period, under the Antonine emperors who ruled until 180 CE, saw consistent stability, development and prosperity.