When I create a map, my first thoughts are: "okay, now what kind, what style, what period of time is the most relevant to start?" and this piece proves me that I should sometimes train to mix a number of references.
The global quality of the picture is impressive, but the most interesting point is this balance between dark and modern ages that makes its unique look; I particularly love these very early medieval shapes on the lands surrounded by precious renaissance-like patterns and very modern presentation of scales, symbols and colors.
The only little one thing that distubs me would be the font used, because it doesn't make sense even in current complex maps. But it really doesn't spoil the global visual idea.

A very good-looking map in my opinion, and I would love a higher resolution version to see all the little details <img src="e.deviantart.net/emoticons/w/w…" width="15" height="15" alt="" data-embed-type="emoticon" data-embed-id="387" title=" (Wink)"/>