How did Croydon get its name?

There are two possibilities cited for the origin of the name of the town Croydon. One theory is that the name Croydon came originally from the Anglo-Saxon croh, meaning "crocus" and denu 'valley', indicating that, like Saffron Walden in Essex, it was a centre for the collection of saffron - a valuable spice. The other view is that the name is derived from the Old French croie dune, meaning "chalk hill",