Dioscorides was a Greek physician who lived in the first century of the Christian era. He became a military surgeon under the Roman Emperor Nero and was a contemporary of Pliny. He wrote De Materia Medica (about 77 A.D.) which gave medicinal properties and some botanical information for about 600 plants. This book was not scientific as were those of Theophrastus. However, for about 1500 years, it was the supreme authority due to the practical nature of its contents, and it has been called the "most successful botanical textbook ever written." Dioscorides was believed to have had his medical training in Alexandria. He traveled widely and made observations on plants from the standpoint of their medical uses.