The Riemann-Hilbert approach for the equations PIII(D 6 ) and PIII(D 7 ) is studied in detail, involving moduli spaces for connections and monodromy data, Okamoto-Painlevé varieties, the Painlevé property, special solutions and explicit Bäcklund transformations.1 0 c 1 1 , 1 c 2 0 1 , where α = e πiθ . Their product (in this order) is the topological monodromy top 0 at z = 0.2. C((z −1 )) ⊗ M has a basis E 1 , E 2 such that the operator δ M has the matrix 1 4 1 z −1 4 with respect to this basis. Since this differential operator is irreducible, the basis E 1 , E 2 is unique Geometric Aspects of the Painlevé Equations PIII(D 6 ) and PIII(D 7 )