This database describes the 2-closures of the transitive permutation groups of degree 2 to 48. It is a supplement to the paper "A census of small Schurian association schemes". The 2-closures for the transitive permutation groups of degree N are contained in the file "TwoClosuresN". Each line of the file contains the list [ id_1, id_2] where: - id_1 is the transitive identification of the permutation group - id_2 is the transitive identification of the corresponding 2-closure In GAP the group G is obtained by TransitiveGroup(N, id_1) and the group H is obtained by TransitiveGroup(N, id_2). The group H is conjugate in S_N to the 2-closure of G.