%0 Journal Article %T A new maximally supersymmetric background of IIB superstring theory %A Matthias Blau %A Jos¨¦ Figueroa-O'Farrill %A Christopher Hull %A George Papadopoulos %J Mathematics %D 2001 %I arXiv %R 10.1088/1126-6708/2002/01/047 %X We present a maximally supersymmetric IIB string background. The geometry is that of a conformally flat lorentzian symmetric space G/K with solvable G, with a homogeneous five-form flux. We give the explicit supergravity solution, compute the isometries, the 32 Killing spinors, and the symmetry superalgebra, and then discuss T-duality and the relation to M-theory. %U http://arxiv.org/abs/hep-th/0110242v1