Radially expanding a tubular such as a liner or casing, especially in a downward direction. The apparatus includes at least one driver device such as a piston that is typically fluid-actuated, and an expander device is attached to the or each driver device. Actuation of the or each driver device causes movement of the expander device to expand the tubular. One or more anchoring devices, which may be radially offset, are used to substantially prevent the tubular from moving during expansion thereof.