Nearly-Kahler 6-manifolds form a distinguished class of Einstein 6-manifolds which are intimately related to G2-holonomy metrics and real Killing spinors. At present, the only known compact, simply-connected examples are homogeneous or cohomogeneity-one. In this talk, we set the foundations for the study of cohomogeneity-two examples. In particular, we show that the acting Lie group must be a finite quotient of SU(2) x U(1), and prove that such nearly-Kahler metrics exist locally in abundance. Time permitting, we'll indicate some directions for the construction of compact examples.