. This paper develops a taxonomy of qualitative spatial relations for pairs of regions, which are all logically defined from two primitive (but axiomatised) notions. The first primitive is the notion of two regions being connected, which allows eight jointly exhaustive and pairwise disjoint relations to be defined. The second primitive is the convex hull of a region which allows many more relations to be defined. We also consider the development of the useful notions of composition tables for the defined relations and networks specifying continuous transitions between pairs of regions. We conclude by discussing what kind of criteria to apply when deciding how fine a taxonomy to create. 3 The support of the SERC under grant no. GR/G36852 and GR/H 78955 is gratefully acknowledged. Thanks are also due to Brandon Bennett, John Gooday and Nick Gotts for useful comments. y Randell is now at the Dental School, Birmingham and Cui is now at ICRF, London. 0 1 Introduction Although the us...