A partial phase diagram of the potassiumN-tetradecanoyl-L-alaninate/decanol/water (+10 per cent CsCI) system has been charted using polarizing microscopy, laser diffraction, and NMR spectroscopy. At low amphiphile concentrations, a chiral nematic ChDphase with disc-like micelles occurs and at higher concentrations there occur a chiral nematic, ChCphase with cylindrical micelles and a chiral version of a dimensionally-ordered (probably rectangular or hexagonal) phase. Between the Chcphase and the genuine isotropic liquid there is a chiral isotropic phase which appears to be a micellar analogue of a thermotropic blue phase. This isotropic chiral Icphase showed flow birefringence.