The Gregynog Natural Products Symposia were initiated by Professor Cedric Hassall in 1967 and have been held each year since then. Their object is to promote communication between research workers who study the chemistry of the products and processes of life. With the increasing participation of scientists from mainland Europe, the Symposium was renamed the European Symposium on Bio-organic 91AV (ESBOC) in 1971, and the European Symposium on Biological and Organic 91AV in 2010.