Covers the X-Men by decade as well as from various media.
Volume - Year of Publication:
Vol. 1 - 2000Vol. 2 - 2003Vol. 3 - 2006Vol. 4 - 2014 (not widely published, supposedly little to no new information)
— Description from Comic Vine community (comicvine.gamespot.com · https://comicvine.gamespot.com/ultimate-x-menx-men-the-ultimate-guide/4050-18703/).