The Roman scholar, Galen (131 AD–200), compiled the 1st list of medicinal plant drugs with similar or identical action (parallel drugs); well, except as time wore on, not all of them were exactly parallel, causing a few surprises & perhaps disappointments along the way. Galen also introduced several new plant drugs, that Dioscorides had not described like the bearberry leaf (Uvae ursi folium,) which is still used as a mild diuretic today. Galen had many more successes than failures.
Galen was a physician & philosopher, probably the most well-known doctor in the Roman Empire, whose theories dominated European medicine for 1,500 years. Claudius Galen was born in Pergamum (modern-day Turkey) to Greek parents. He studied in Greece, in Alexandria & other parts of Asia Minor & returned home to become chief physician to the gladiator school in Pergamum, gaining practical experience of treating the wounds from the often bloody warrior sport.
In the early 160s AD, Galen moved to Rome to work; & with the exception of a brief return to Pergamum, spent the remainder of his life in the Roman capital. There he became physician to emperor Marcus Aurelius & would later serve in the same role to Aurelius's successors, Commodus & Septimius Severus.
Galen introduced the experimental method of medical investigation in the Roman empire. Throughout his life dissected animals in his quest to understand how the body functions. His most important discovery was was not in the field of medicinal plants, but that arteries carry blood, although he did not discover circulation.
Galen was prolific, with hundreds of treatises attributed to his name. He compiled the significant Greek & Roman medical thought to date, & added his own discoveries & theories. His influence reigned over Western medicine for 15 centuries after his death. It was not until the Renaissance, that many of his theories were refuted.
