The properties of a classical stellarator will be described and the need to optimise stellarators will be motivated. The principles of optimisation will be presented. W7-AS, a partly optimised modular stellarator, will be briefly introduced and some results with relevance to its optimised properties will be summarised. The fully optimised large stellarator W7-X will be described and the progress in optimisation from W7-AS to W7-X will be discussed. The possible design of an optimised stellarator reactor will be presented.