Novel bainitic microstructures, consisting of slender ferrite plates (tens of nm) in a matrix of retained austenite, have reported maximum yield strength of 1.4 GPa, ultimate tensile strength of 2.2 GPa, 30% ductility and respectable levels of fracture toughness (∼51 MPa m0.5). The unusual combination of properties is attributed to the fine bainitic plates and the presence of retained austenite in the microstructure.The authors acknowledge financial support from the Spanish Ministerio de Educación y Ciencia for the financial support in the form of Ramón y Cajal contracts (RyC 2002 and 2004 respectively). Some of this work was carried out under the auspices of an EPSRC/MOD sponsored project on bainitic steels at the University of Cambridge; we are extremely grateful for this support over a period of three years. The authors are extremely grateful to Prof. H. K. D.Peer reviewed