The synthesis and the mesomorphic properties of liquid crystalline polymer networks and the linear polymers upon which networks are based are reported. The linear polymers, synthesised from trimellitic acid, 2-allyl ester with the appropriate 4,4'-1,n diphenoxyalkane, exhibit a nematic mesophase, as indicated by calorimetric analysis, X-ray diffraction data, and polarising microscopy. Polymer networks were prepared from the linear polymers in the anisotropic state by thermal crosslinking in the bulk producing a very stable liquid crystalline phase.