A main-chain non-racemic chiral liquid crystalline polymer has been synthesized from (R)-(-)-4'-{omega-[2-(p-hydroxy-o-nitrophenyloxy)-1-propyloxy]-1-nonyloxy}-4-biphenyl carboxylic acid, abbreviated PET(R*)-9. Based on differential scanning calorimetry, wide angle X-ray diffraction (WAXD) and polarized light microscopy experiments, this polymer undergoes at least three liquid crystalline (LC) transitions in addition to crystallization. The LC transition sequence is I <->(3.21 kJ/mol) (1.85 degrees C) TGBA* <->(1.27kJ/mol) (1.75/kJ/mol) S-A* <->(0.35 kJ/mol) (130 degrees C) S-C* <->T-37 degrees C(g) The transition sequence is reversible since they are LC phases, which are close to thermodynamic equilibrium. Among these phases, the twisted grain boundary smectic A (TGBA*) phase is, for the first time, found in a main-chain LC polymer. The TGBA* is only stable within a temperature region of 10 degrees C between the Smectic A* (S-A*) phase and the isotropic melt. Crystallization that takes place in the (S-A*) phase can form both hat-elongated and double-twist helical single lamellar crystals, as observed by transmission electron microscopy (TEM). Analysis of the WAXD fiber patterns of this polymer indicates that the crystal structure of PET(R*)-9 in the bulk is orthorhombic, identical with that determined using selective area electron diffraction in TEM [Macromolecules 32 (1999) 524; Phys Rev B 60 (1999) 12 675].