Delft Blue Vase

I picked this up today knowing full well after trying to research another piece for a friend, that Delft pottery is very difficult to ID unless it is from one of the big manufacturers. I looked around and could only find one other piece with Eureka on it, which looked nothing like this one so I know that is not the pattern name or form. Could be the pottery or artist (not likely) unless it was made in a castle :)