Ptolemy's Canon

Ptolemy from whence the name comes, was an astronemer who used astronomical events to create a list of kings and dates of their reign from Assyrian times through the successors of Alexander.

It is considered to be not absolutely perfect, but essentially correct (i.e. does not contain Neriglissar's accepted successor Labashi-Marduk, or the debated Cyaxares II).

External Links

Ptolemy's Canon, https://www.livius.org/articles/concept/ptolemys-canon/