The Collaborative International Dictionary of English v.0.48:

Soever \So*ev"er\
   A word compounded of so and ever, used in composition with
   who, what, where, when, how, etc., and indicating any out of
   all possible or supposable persons, things, places, times,
   ways, etc. It is sometimes used separate from the pronoun or
   adverb.
   [1913 Webster]

         For unto whomsoever much is given, of him shall be much
         required.                                --Luke xii.
                                                  48.
   [1913 Webster]

         What great thing soever a man proposed to do in his
         life, he should think of achieving it by fifty. --Sir
                                                  W. Temple.
   [1913 Webster]