COST 238 (prediction and retrospective ionospheric modelling over Europe-PRIME) was a four-year project sponsored by the European Commission initiated in March 1991 and involving some 72 research workers from 31 organisations in 17 countries. The objectives, embodied in the agreed Memorandum of Understanding were: “to develop techniques for using ionospheric sounding information taken from existing measuring equipment to generate improved models of the European ionosphere, needed to estimate ionospheric propagation effects on telecommunication systems”. The author considers some of the results. (6 pages)