When Atarshumki I was king of Bit Agusi what was the name of the capital?
Bit Agusi Bit Agusi (also written Bet Agus) was an ancient Aramaean Syro-Hittite state, established by Gusi of Yakhan at the beginning of the 9th century BC. It had included the cities of Arpad, Nampigi (Nampigu) and later on Aleppo. Arpad was the capital of the state-kingdom. Bit Agusi stretched from the A'zaz area in the north to Hamath in the south.
History of Baghdad The city of Baghdad (Arabic: بغداد‎ ‎ "Baġdād ") was founded in the mid 8th century as the Abbasid capital, following the Abbasid victory over the Umayyad Caliphate. It replaced the Sassanid capital of Seleucia-Ctesiphon some 35 km to the south-east, which was mostly depopulated by the end of the 8th century.