Judging from merely external considerations, the Books Contra Eunomium constitute one of the most important sources for the understanding of the thought and doctrine of St. Gregory, Bishop of Nyssa. They form the greater bulk of his dogmatic writings; and they were written to carry on the work of his older brother and «master», St. Basil of Caesarea, whose untimely death on January 1, 379, launched Gregory to be one of the foremost leaders of Orthodoxy.