Wine came to Europe with the spread of the Greek civilization around 1600 BC. Homer's Odyssey and Iliad both contain excellent and detailed descriptions of wine. Wine was an important article of Greek commerce and Greek doctors, including Hippocrates, were among the first to prescribe it. The Greeks also learned to add herbs and spices to mask spoilage. The foundation and strength of viniculture in Western Europe are primarily due, however, to the influence of the Romans. Starting about 1000 BC, the Romans made major contributions in classifying grape varieties and colors, observing and charting ripening characteristics, identifying diseases and recognizing soil-type preferences. They became skilled at pruning and increasing yields through irrigation and fertilization techniques.