Amman

Amman is an ancient Middle Eastern city.

In Biblical times, Amman was the capital of the Ammonites, a Semitic people speaking a language very similar to that of their Moabite and Hebrew neighbors and sharing many cultural traits with them - which did not prevent their often going to bloody war. The Ammonites disappeared as distinct people with the rise of successive empires which dominated the the region for many centuries - Assyrians, Babylonians, Persians, Hellenists and Romans - but their memory was preserved in the name of the city which had been their capital. It had many ups and downs in its history, alternately flourishing and shrinking. In the 20th Century Amman became the capital of the Kingdom of Jordan and one of the main cities of the Middle East.

Amman in Occupation Duty
Amman was the most western outpost of the Arabs, closest to the territory of the Philistines. That gave Amman a considerable strategic importance, should Arab support for the rebellious Moabites flare into all-out war with the Philistines.

Editorial note
The Ammonites are nowhere mentioned as still being a distinct people at the time of the story. Presumably they were assimilated - either by the Moabites, as were the Hebrews, of by the Arabs. From the meager information provided it is impossible to determine if the Arabs of Amman were politically part of Arabia - a major oil-producing power - or a separate prnicipality.