I must admit I was thrown off at first when I saw the synopsis. Two brothers, shounen ai?! But thus far, that element is barely there.
The older brother, Robert, is the serious thinker of the two, while Emile, the younger, is the ladies' man. They make a great combination, and there are no end of funny moments from Emile getting into hot water and Robert yelling at him in exasperation. The Prince is never serious either, poking fun at Robert whenever possible. Definitely a cast that you'll like instantly.
The story is very much focused on Robert and Emile's problems at court and exploits, so it feels like episodes strung together to highlight different things that had happened to the brothers. At the moment it's very cut and dried, but considering there are currently 6 volumes out, something more in-depth will definitely develop. The historical element makes it even more interesting.
The art is very nice at certain points, but on the whole rather inconsistent, in particular the colour images. These problems are minor, however, and it's pretty enough in general for you to make allowances. This is looking like a very promising manga, and I can't wait for more volumes to be scanlated so that I can see where it's heading.