  The edge-on, nearby spiral galaxy NGC5907 has long been used as the prototype
of a ``non-interacting'' warped galaxy. We report here the discovery of two
interactions with companion dwarf galaxies that substantially change this
picture. First, a faint ring structure is discovered around this galaxy that is
likely due to the tidal disruption of a companion dwarf spheroidal galaxy. The
ring is elliptical in shape with the center of NGC5907 close to one of the
ring's foci. This suggests the ring material is in orbit around NGC5907. No
gaseous component to the ring has been detected either with deep H$\alpha$
images or in Very Large Array (VLA) HI 21-cm line maps. The visible material in
the ring has an integrated luminosity <= 10^8 L_sun and its brightest part has
a color R-I ~ 0.9. All of these properties are consistent with the ring being a
tidally-disrupted dwarf spheroidal galaxy. Second, we find that NGC5907 has a
dwarf companion galaxy, PGC54419, projected to be only 36.9 kpc from the center
of NGC5907, close in radial velocity (\Delta V = 45 km s^{-1}) to the giant
spiral galaxy. This dwarf is seen at the tip of the HI warp and in the
direction of the warp. Hence, NGC5907 can no longer be considered
``non-interacting,'' but is obviously interacting with its dwarf companions
much as the Milky Way interacts with its dwarf galaxies. These results, coupled
with the finding by others that dwarf galaxies tend to be found around giant
galaxies, suggest that tidal interaction with companions, even if containing a
mere 1% of the mass of the parent galaxy, might be sufficient to excite the
warps found in the disks of many large spiral galaxies.
