Abstract: The present invention relates to a process for the dehydration of one or more alcohols, which process comprises contacting one or more alcohols in the presence of one or more ethers with a supported heteropolyacid catalyst, characterised in that: (i) the heteropolyacid is tungstosilicic acid in the form of the free acid and supported on a silica support, (ii) said supported heteropolyacid catalyst has a heteropolyacid loading of from 0.5 to 0.9 mg/m2 of catalyst support surface area, and (iii) that said process comprises passing the one or more alcohols and one or more ethers in the vapour phase over a bed of the supported heteropolyacid catalyst at a temperature between 200° C. and 280° C.