Of all the ancient civilizations, the Egyptian one was definitely the first of which we have a good knowledge of how they used herbs and plants for medicinal reasons. Sure, everything we know is a bit vague, but we have some ideas.
The first Egyptian physician we know was called Imhotep and worked for the pharaohs of the third dynasty, around 3000 years BC. We also know about him that he was an astrologer and had the ability to cure many diseases.
Obviously our knowledge is partly based on legends, anyone who was able to cure diseases was considered a magician and therefore seen as if an almost divine character, a magician and for his healing powers. But in general in Egyptian civilization, medicine and religion went hand in hand. So it wasn’t just the medicines that healed but the gods through medicines.
The concept of active ingredients, chemistry and pharmacology are modern concepts that were not found in Egyptian medicine. Another aspect of Egyptian culture that developed knowledge of the properties of herbs and plants was mummification. In fact, many substances that we use even now were used to mummify and perfume.
The interesting thing is the use of certain plants or natural remedies such as frankincense or myrrh (which would be the resins of plants and therefore require a little processing) which are still used today. They certainly used different essential oils such as peppermint, camphor and others that we also use.
Frescos have been found in Egyptian times showing the production and use of essential oils. Of course, even in this case everything was very much linked to religion.
Another thing we know for sure because papyri have been found, such as Ebers’s, which list the medicines that were recommended to a patient, were basically the ancestors of our medical prescriptions. Obviously not all medicines were plants, the Egyptians also used minerals as medicine but the majority were undoubtedly of vegetable origin.