The oldest known astronomical atlas -- ca. 667 CE ! Answered
I ran across a preprint today which I find wonderfully impressive. It documents a Chinese astronomical atlas prepared some time between 649-684 CE (AD, for the oldsters) , and covering the complete visible sky of the Northern Hemisphere. Star positions are accurate to within a couple of degrees (with naked eye observations). As the authors write in their abstract,
This set of sky maps (12 hour angle maps in quasi-cylindrical projection and a circumpolar map in azimuthal projection), displaying the full sky visible from the Northern hemisphere, is up to now the oldest complete preserved star atlas from any civilisation. It is also the first known pictorial representation of the quasi-totality of the Chinese constellations.