Thisvolumeisthefruitofaninstructionalconferenceonalgebraicnumbertheory,heldfromSeptember1sttoSeptember17th,l-965,intheUniversityofSussex,Brighton.ItwasorganizedbytheLondonMathematicalSocietyundertheauspicesandwiththegenerousfinancialaidoftheInternationalMathematicalUnionandoftheAdv