  This is the first of a series of works devoted to investigate cool dwarfs in
wide multiple systems. Here, I present Koenigstuhl 4 A and B, two bright,
intermediate M dwarfs with a common high proper-motion and separated by 299
arcsec. At the most probable distance of the system, 19 pc, the projected
physical separation is 5700 AU, which makes Koenigstuhl 4 AB to be one of the
least bound binary systems with late-type components found to date. I also
associate the primary with a ROSAT X-ray source for the first time.
