This work is a new study that builds on the author's 1991 monograph, "Beiträge zur mittelassyrischen Chronologie und Geschichte." It includes new evidence from the M4 text group, the archive for the management of sacrifices at the Assur temple, but it is also new in its own right, in spite of many references to previous research and the repetition of and agreement with some earlier findings. The significant difference between this and previous research, however, is that archive M4 provides a timeframe for the reevaluation of the texts: the period between Tukultī-Ninurta I and Tukultī-apil-es̆arra I, whose reigns more or less bracket the 12th century BC.