The first NATO Advanced Study Institute on Nitrogen Ceramics held in 1976 at Canterbury came at a particularly significant moment in the development of this subject. The five-year period, 1971-75, had been an especially fruitful one in very many respects for work in the areas of covalent materials in general, and of the nitrides in particular. The Institute was therefore able to cap­ ture fully the spirit of excitement and adventure engendered by the outputs of numerous national research programmes, as well as those of many smaller research groups, concerning ceramics potent­ ially suitable for applications in a high temperature engineering context. It reflected accurately the state of knowledge with respect to the basic science, the powder technology, and the properties of materials based on silicon nitride and associated syst­ ems. The Proceedings of the Institute thus provided a good record for workers already in the field, and a useful textbook for new­ comers to the subject of nitrogen ceramics. The Canterbury Advanced Study Institute had a valuable educ­ ational and social function in bringing together for two weeks a large proportion of those workers most closely involved at that time with the nitrogen ceramics. The atmosphere of this meeting, providing both intensive discussions and informal contacts, made a lasting impression on the participants, and inevitably the question was raised of whether, and when, a second Advanced Study Institute might be held on this subject.