Medical schools known as Bimaristan began to appear from the 9th century in the medieval Islamic world among Persians and Arabs and they were generally more advanced than those in medieval Europe at the time. As a trading culture, the Arab travellers had access to medical knowledge and plant material from distant places such as India and China. Herbals, medical texts and translations of the classics of antiquity filtered in from east and west. Charaka Samhita and Sushruta Samhita from India were translated into Arabic during the Abbasid of Caliphate (750 AD). Botanists and physicians from the Islamic world significantly expanded on the earlier knowledge of materia medica. For example, Al-Dinawari described more than 637 plant drugs in the 9th century and Ibn al-Baitar described more than 1,400 different plants, foods and drugs in the 13th century.

Avicenna’s The Canon of Medicine (1025 AD) lists 800 tested drugs, plants and minerals, and the healing properties of herbs including nutmeg, senna, sandalwood, rhubarb, myrrh, cinnamon and rosewater are discussed in it. Its Latin translation of the 12th century was a text book of European medical institutes for long. In it Avicenna expresses his indebtedness to Indian doctors and quotes verbatim from Ayurvedic treatises. Baghdad was an important centre for Arab herbalism, as was Al-Andalus between 800 and 1400.

With numerous drugs and spices entering the Arabic world, the flourishing Islamic civilization saw the development of newer and sophisticated palatable medicines, which required elaborate preparation. The specialists who engaged in this were the occupational forerunners of today’s pharmacists.

In European countries exposed to Arabian influence such as Spain and southern Italy public pharmacies began to appear. In 1240 Frederick II of Hohenstaufen, who was Emperor of Germany as well as King of Sicily, codified the responsibilities and the practice of Pharmacy as separate from those of Medicine.

The Book of Simples, authored by Abulcasis (936–1013) of Cordoba is an important source for later European herbals, while the Corpus of Simples, by Ibn al-Baitar (1197–1248) of Malaga is the most complete Arab herbal, which introduced 200 healing herbs including tamarind, aconite and nux vomica. Other pharmacopoeia books include those written by Abu-Rayhan Biruni in the 11th century and Ibn Zuhr (Avenzoar) in the 12th century (printed in 1491). The origins of clinical pharmacology also date back to the Middle Ages in Avicenna’s The Canon of Medicine, Peter of Spain’s Commentary on Isaac, and John of St Amand’s Commentary on the Antedotary of Nicholas. The continuing importance of herbs for centuries after the Middle Ages is indicated by the hundreds of herbals published after the invention of printing in the 15th century. Theophrastus’s Historia Plantarum was one of the first books to be printed, but Dioscorides’s De Materia Medica, Avicenna’s Canon of Medicine and Avenzoar’s Pharmacopoeia were not far behind.

The 15th, 16th and 17th centuries were considered the great age of herbals, as many works on herbals began appearing for the first time in English and other languages rather than in Greek or Latin. The anonymous Grete Herball of 1526 was the first herbal to be published in English. The Herball or General History of Plants (1597) by John Gerard and The English Physician Enlarged (1653) by Nicholas Culpeper are among the other best known herbals in English.