The domain structure of Pb(Mg1/3Nb2/3)O-3-60%PbTiO3 (PMN-60%PT) was investigated by polarized light, piezo-force, and transmission electron microscopies. Two sets of stripe-like domain patterns were observed with < 011 >-type twin walls, which were geometrically arranged within larger domain platelets. Upon application of an electric field E along a direction that was different than that of the spontaneous polarization, the domain platelets were destabilized, favoring one set of domain striations over another. Interestingly, on removal of E, the original domain structure was not recovered: revealing a history dependence.