The mood starts with the Gothic arches chosen for the fireplace surround and doorway and demonstrated more vividly with the window.
Though not common, this window style is available from more than one manufacturer and a number of companies have window coverings that will work well for it.
The next design choice that supports the medieval look comes from the slate floor. With its varied texture and color from one piece to the next, it is consistent with the feeling that this room comes from an earlier time. A floor with this much character is not merely a background element but at the very least a strong supporting player for the rest of the décor.
The stone carvings and tapestry on the walls mirrors the medieval. Several catalogs and online stores carry this type of art. Tall candlesticks with candles and greenery also suit the room. The final touch comes from the choice of tapestry-patterned spreads on the upholstered pieces. Is your home your castle? With a few ideas from this space, it can look more like it!