I don’t know Spainish, but I know that de means of. I think that de Castelle mean of castle. Pardon me if I’m totally wrong.
Well, last names are De Peña, De Castillo, De Flores and De Rivera. They are common in spain, just without the De xD
They mean of/from Crag, of/from Castle, of/from Flowers and of/from Brook. I am from Málaga, Spain, so I know at least a bit what I am talking about xD
I had known two women who had Latin/Hispanic roots and their last names were Florez and Castille. Miss Castille told me that most people thought that she was a banger, because of her last name. I kinda knew that Florez meant Flower, because of Harry Potter. LOL