Examples of engineering artefacts made with modern composite materials are given, followed by a brief discussion of the range of physical properties attainable by fibre composites. Physical properties are usually simply additive but the strength properties are not. Multiple fracture is discussed in detail to show how cracks can be used to confer microductility and to provide energy absorbing structures. This opens the way for the use of ceramic materials as high temperature substitutes for metals. A possible microstructure for very high temperature creep resistance is discussed in detail; it consists of alternate layers of single crystals od differing lattice constant and elastic modulus. Finally the concept of a smart material is discussed showing how structures may be monitored with fibres and their mechanical response controlled or modified.