According to a Babylonian Chronicle, Shalmaneser V died in the month of Ṭebētu (X) during the fifth year of his reign (722) and Sargon II ascended the throne on the twelfth day of that month. Sargon was a son of Tiglath-pileser III and thus a brother of Shalmaneser. It was likely not a peaceful transition of power since Sargon soon thereafter had over six thousand Assyrians deported to Hamath, possibly because they had not supported him. Sargon was to reign over Assyria for seventeen years, being killed while on campaign in 705 and being succeeded by his son Sennacherib, who took the throne on the twelfth day of Abu (V) in that year. The Assyrians lost control over Babylonia almost immediately upon Sargon's accession, with the Chaldean Marduk-apla-iddina (II) (Merodach-baladan) taking the throne of Babylon in the first month of 721. Only in 710 was Sargon able to drive the latter out of Babylon and, in 709, capture his tribal stronghold of Dūr-Yakīn in the marshland at the head of the Persian Gulf. Babylonian King List A and the Ptolemaic Canon thus credit Sargon with a reign of five years (709–705) over Babylonia, with his first full year of reign in Babylon (709) being his thirteenth year on the throne of Assyria.
Grant Frame
Grant Frame, 'Introduction', RINAP 2: Sargon II, Sargon II, The RINAP 2 sub-project of the RINAP Project, 2021 [http://oracc.org/rinap/rinap2/rinap2introduction/]