National Grid, the Transmission System Operator for Great Britain, has recently installed a Wide Area Monitoring System (WAMS), to improve the real-time view of the power system. Phasor Measurement Units (PMUs) have been installed, primarily through upgrades to digital fault recorders, as an extension to dynamic system monitoring. This paper reviews the development of WAMS on the GB System and presents the experiences so far, detailing both existing and future applications of synchrophasor technology, such as oscillation analysis, model validation and improved situational awareness.