A princess and Witch.. This reminds me of a strange world war inspired anime called Izetta Chan or something like that, decent anime too. I wouldn't call it a Yuri, maybe subtext with good Yuri goggles.
It's "Izetta: The Last Witch", just watched it not too long ago actually. And odd pseudo-WW2 setting aside, it's really quite good and the yuri is solid too, you honestly don't even need goggles for it. They even have a "spending the night together before the big fight" scene, it's so fucking gay xD