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
The fusion of Nabatean, Hellenistic and Roman styles also characterizes the architecture of the region. "Hawrani"-style architecture is dated to at least the 1st century CE when the Nabateans moved their capital from Petra to Bosra. The Nabateans were avid builders with their own distinctive architectural tradition. After the Roman annexation of the Nabatean Kingdom in 106, the area experienced a building boom that lasted until the onset of strife and instability in the mid-3rd century. Though the Roman contribution was highly influential to the region’s architecture, the Hauran’s Nabatean inhabitants largely maintained their own building traditions, particularly in the smaller towns.