Agsu () is a city in and capital of the Agsu District of Azerbaijan.
History
Abbasgulu Bakikhanov noted that Nadir Shah issued an order for resettlement of the inhabitants of Shamakhi to new laid down city on the bank of Agsu river, in 1735. At present, the name of Agsu city (which is the centre of Agsu district) is shown as New Shamakhi in some sources. It is related with resettlement of the inhabitants of Shamakhi to Agsu city. Since that time, historic Shamakhi has been called Old Shamakhi, Agsu – New Shamakhi.
The name of the city existing in the 18th century was frequently shown as Agsu deriving from "Agsuchay". "Ruined city" – ruins of the Agsu city of the memory of the 18th century is located in the north of Agsu city.
S. Bronevski noted that the city was fenced with fortress walls, with a trench dug outside them. The castle had quadrangle and round towers. The lower parts of the houses consisted of basements and the upper parts of the dwellings tumbled down onto these basements. Holes are the remainders of the basements and houses. The dwelling buildings were erected very close to each other. The streets were narrow and transport with wagons was not possible. Though the central streets were comparatively wide.
Earthenware of the Middle Ages and a coin minted with the name Surkhay Khan were found in Agsu city. The coin had been minted before Nadir Shah's order about laying out the city. But it raises the probability of the creation of Agsu city on the base of an already existing Agsu village. At the same time, materials and ceramic goods belonging to 100–150 years before occupation of Shamakhi by Nadir Shah were found during initial research in the "Ruined city". Perhaps, Nadir Shah had issued an order for additional works after the resettlement of the inhabitants in the village.
Agsu city had durable fortress walls and defensive towers in the 18th century. The city had gradually developed and it had become one of the largest cities of Azerbaijan at the end of the 18th century. V. Leviatov noted that when population of New Shamakhi (Agsu) had reached nearly 10 thousand, the population of Gandja, Ardabil, Shusha, Nukha, Baku and other cities had not been over 3 to 8 thousand.
Agsu city was one of the leading cities in the socio-political and military life of Azerbaijan at the end of Middle Ages. In 1734, Nadir Shah attacked Shamakhi with his troop. The inhabitants of Shamakhi resisted against the attack, notwithstanding the fact that Surkhay khan had left the city. In August 1734, Nadir Shah's troop overcame the resistance and the city was burnt. In 1735, Nadir Shah issued an order about laying out the new city on the bank of Agsuchay river. After construction of the new city, the inhabitants of Shamakhi were resettled here; the residences of the rulers of Shamakhi also were moved here.
In 1743, the inhabitants rebelled against the Nadir Shah's yoke. Liar princes of Safaviler – I, II, III Sam Mirzas came out. Two of them operated in Shirvan. I Sam Mirza occupied New Shamakhi (Agsu) to the accompaniment of Surkhay Khan's troop of fifty thousand. He revoked taxes imposed by Nadir Shah. But, I Sam Mirza was killed in the war by the son of Nadir Shah, Nasrullah Mirza.
II Sam Mirza made a great rebellion in Shirvan together with Mohammad (the son of Surkhay), in 1743. People of Agsu banished Iranian officials from the city. But, despite three defeats, Nasrullah occupied Agsu castle. Based on source, Persians encircled the city. The city was occupied after some days later and people were killed. Nadir Shah had called this day "Allah dad" (God, help me).
There were organized independent khanates after the death of Nadir Shah (1747). The one of the khanates was Shirvan (1747–1763) which its supremacy was diarchy. At this time, feudal lords struggled against each other in Azerbaijan, in 1755, Khan of Shaki Hazhi Chalabi Khan encircled Agsu city under existing conditions. Hazhi Chalabi Khan retreated after grievous loss in the war around Agsu. Hussein Ali Khan went back to his khanate, notwithstanding Hazhi Mohammad Ali Khan had given the key of the city to him. In 1762, Transcaucasia was shrouded in plague.