[2] In the first century of the Christian era this insignificant city (then Gerasa) experienced a fast ascent under Roman rule and the Pax Romana.

[3] Starting in the middle of the 1st century, this upswing led to active building and a rich abundance of architectural monuments, still impressive today.

Well-made roads were built to Pella, Philadelphia (now Amman), Dion and to the provincial capital Bos(t)ra.

The average yearly rainfall in the governorate is in the range of 400–600 mm considered among the highest in the country.

[4] The elevation range of the province is 300 to 1247 m above sea level with fresh water streams and the Zarqa River flowing through it.

Jerash Governorate consists of a single district (liwa'), Jerash Liwa, that is divided into three sub-districts (qda'):[5] Aside from the city of Jerash that gives the governorate its name, the governorate has many cities and towns: Souf, Sakib, Borma, Al-Mastaba, El-Kitté, Al-Haddadé, Bellila, Deir Il-Liyat, Nahlé, Il-Kfeir, Rashaida, Raimoun, An-Nabi Houd, Al-Jazzazah, Jubbah, Mirse', Muqbila, Al-Msheirfeh, Qafqafa, and others.

Jerash is equidistant (40 km) from the largest three cities in Jordan (Amman, Irbid and Zarqa), and this proximity makes the governorate a good business location.