History of Essential Oils
Essential oils or Aromatic Oils as they are popularly known, have been used across the globe for centuries. Between different regions and cultures, their usage varied from religious purposes to medicine. It is estimated that oils derived from plants have been in use as early as 18000 BC.
Use of Essential Oils in Egyptian, Greek & Roman Civilisations
Egyptians used plant extract as perfumes and cosmetics apart from using them in religious rituals and for healing the sick. Without the effect of essential oils, much of Egyptian culture would have remained unknown to us. It is believed that in Ancient Egypt, the dead were rubbed with cedarwood oil, which has a preservative effect (mummification). Cedarwood was also the key element which helped in preservation of the ancient papyrus scroll.
Cedarwood oil was also used for fragrance and as an ingredient for hair and skincare. When the Greeks and Romans conquered the Egyptian empire, they also acquired the knowledge of aromatic essences and fragranced water. They learned from the Egyptians how to extract oils from different plants. The Greeks and the Romans made use of distillation processes to obtain essential oils. The Greek scientist Hippocrates, who is considered as the spiritual father of modern medicine, was a strong supporter of essential oils for medicinal purposes.
Usage of Aromatic Oils in Middle age
The revival of aromatherapy in the 11th century is attributed to the invention of Persian alchemist and physicist Ibn Sina, also known as Avicenna. Ibn Sina is credited with invented a condensing coil for steam distillation, which made essential oil distillation much more systematic and productive. Due to this, Aromatic Oils started regaining their lost popularity. It is for this reason that, Ibn Sina, is also known as “father of early modern medicine”. His book "Canon of Medicine" was the most significant textbook on medicine until the 16th century. In this book, he has strongly advocated the usage of essential oils and infusions to treat physical and mental illnesses.
The number of plants used to produce essential oils increased dramatically in the 15th century, which included oils from rose, juniper, sage, rosemary, lavender, etc, which are popular even today. Around 1500, swiss alchemist and physician, Paracelsus, conducted extensive research on pure natural oils. He is believed to be a pioneer in many areas of “medical revolution” of the Renaissance and he emphasized the use of plant based natural essences into his remedies.
Discovery of Aromatherapy
The present day term "aromatherapy" was accidently conceived by the famous French chemist Rene-Maurice Gattefosse in 1935. As per historians, the famous chemist / scientist accidently burnt his hand during a chemical experiment and as a reaction quickly drowned his burnt hand in the nearest kept barrel which contained lavender essential oil. He was surprised to see his burnt arm did not pain, healed really fast and also left no scars. He spent the rest of his life studying pure natural oils for medical and cosmetic purposes. The book "Aromatherapy," which was written by him in 1939, is referred even today.
In 1929, Sévelinge, a pharma enthusiast from Lyon, exhibited the antibacterial property of essential oils. Subsequently, in the 1950s, essential oils were used by a military physician in Indochina to cure injured soldiers. Thus, Aromatherapy started gaining much deserved popularity and people started realizing its importance. In 1975, Pierre Franchomme, a pharmacologist made significant progress by suggesting the concept of "chemotype," i.e., identifying a plant's true chemical composition. He proposed listing of the dominant aromatic compounds against each plant and how they impacted its properties.

Present day “Aromatherapy”
When we talk about aromatherapy today, we're referring to the use of essential oils to improve psychological or physical well-being. It implies the usage of plant-based oils or essence of oils to improve health and to treat illnesses. Aromatherapy is a type of phytotherapy (plant-based healing) that is now used all over the world.
While we see that Aromatherapy as a science has been with mankind for long, it has grown in popularity over the last 30 years. This is majorly due to several studies done in recent past which demonstrate the effectiveness of essential oils for both the body and the soul. Today, aromatherapy is recognised as a full-fledged branch of medicine.