We provide a method of detecting a power island in a power distribution network of the type comprising: a plurality of distribution lines connecting consumers to electrical power supplied from one or more substations, a plurality of circuit breakers and/or switches each operable to connect and disconnect transmission of electrical power along an associated distribution line, each being associated with a communication device operable to communicate the status of the circuit breaker and/or switch to a monitoring system, and one or more embedded generators each connected to a distribution line within the power distribution network so as to provide electrical power to the power distribution network, the method including the steps of: storing at the monitoring system data representing the connectivity of the distribution network including a status of each circuit breaker and/or switch, receiving at the monitoring system a communication from a communication device that an associated circuit breaker and/or switch is disconnected, determining at the monitoring system, using the data representing the connectivity of the distribution network, whether the disconnection of the circuit breaker and/or switch has resulted in a portion of the power distribution network being electrically disconnected from the remainder of the power distribution network that remains electrically connected to the one or more substations, and identifying the disconnected portion of the power distribution network as a power island within the power distribution network.