A common phrase heard in supposedly eloquent English is "From whence it came". This is incorrect and tautologous language.
Whence is an outmoded word for "from where", and therefore, the preposition from is not required.
Other words in the category include:
Of these, probably only Hence and Therefore are in very common usage today; used in following arguments of logic.
Webster seems to think that it's OK to say 'from whence', but we all know better, don't we kids?
If you're going to speak archaic English, use it correctly!