Semantically, homoeopathy traces its origins to two Greek words, homois meaning similar and pathos for suffering. Historically, the story begins with the ancient Greek physician Hippocrates—the founder of western medicine—who first mooted the idea of curing 'like with like' over 2,500 years ago. Aristotle is also said to have practiced this system and Paracelsus described it in the Middle Ages. The Chinese, Indians, Greeks, Mayans and Native American Indians also used the law of similars.

It was when Hahnemann began working on a project to translate William Cullen's Materia Medica into German that he began his quest for a better way of providing healthcare using the principles of "Similars." While working on this project, he became fascinated with a species of South American tree-bark (cinchona) which was being used to treat malaria-induced fever. Hahnemann experimented by testing certain potions on himself (referred to as provings) and ingested the bark while discovering that it caused symptoms similar to malaria. From these observations, he concluded that minuscule doses of a medicinal substance cured symptoms similar to those that they produced. Besides, every substance not only affected the body, but also the mind and emotions. He, then continued his research into "cures" and the idea of "similar suffering," and began compiling his findings. Similia similibus curentur, the Latin phrase meaning "let likes be cured by likes," is the primary principle of Homoeopathy. A homoeopath searches for a substance that produces in a healthy person those same symptoms a patient experiences. 

Hahnemann re-tested his theory by giving malaria sufferers concoctions of cinchona bark. They improved dramatically! He spent the next six years experimenting on himself, his family and a group of followers including the converts and disciples of his time. Some converted luminaries of homoeopathic science are: Nash, Kent, Clarke, Boerieke, Herring, Hale,  Farrington, Barlet, Boger, Roberto, Wilson, Allen, Lilienthal, Lippe, Komdocrfer, Wesshoeft, Burnett, Cowperthwaire, Bradford and Boeinninghansen. He and his colleagues catalogued over 200 medicines or remedies, primarily of plant, mineral and animal origin. Each remedy was proved, that is, taken by healthy volunteers who kept detailed records of their physical, mental and emotional reactions. The most frequently reported symptoms were compiled in a Materia Medica - a compendium of symptoms that provided detailed information about the working of the remedies.

These 'provings' later crystallized into homeopathy—a term coined by Hahnemann in 1826. He subsequently began treating patients following the principle of Simila Similibus Curentur—let likes be treated by likes. How does the principle of similars work? For instance, to induce vomiting in a healthy individual a large dose of Ipecac is given. Yet, a person suffering from nausea and vomiting improves with a homeopathic dose of Ipecac. 

Or take Allium cepa derived from onions. Contact with raw onions causes lacrimation, stinging and irritation around the eyes and nose. Allium cepa is therefore prescribed to patients with hay fever. 

Around this time, Edward Jenner discovered the technique of injecting small doses of cowpox into healthy people to immunize them against smallpox. Although Jenner's treatment—also based on the law of similars—was accepted by orthodox medicine, Hahnemann's work wasn't! 

The new system began taking rapid strides in the New World after Hans Gram, a Dutch homeopath, emigrated to the USA in 1825. The discipline received a tremendous boost in the 1830s when a cholera epidemic swept Europe. While conventional doctors had a death rate of 50 per cent, homeopaths cured 80 per cent of their patients. Homeopaths also enjoyed tremendous success in treating cases of yellow fever, typhoid and scarlet fever. 

In 1844, the American Institute of Homeopathy (AIH) was formed, America's first national medical society. Alarmed, conventional doctors formed the American Medical Association (AMA) in 1846. Their primary agenda seemed to halt homeopathy in its tracks. The school’s method of treatment became very popular in the early 1900’s. Mark Twain was all praise for the alternative remedy in an 1890 issue of Harpers magazine: "The introduction of homeopathy forced the old school doctor to stir around and learn something of a rational nature about his business." The other advocates included William James, H.W. Longfellow, Nathanial Hawthorne and Daniel Webster. 

Yet, by 1900, there were 22 homeopathic colleges, 100 homoeopathic hospitals, over 1,000 homeopathic pharmacies and 29 different journals devoted to homeopathy had sprung up in the USA. And nearly 20 per cent of doctors were practicing homeopaths. Between 1829 to 1869, the number of homeopaths in New York doubled every five years. Boston University, Stanford University and New York Medical College were among those educational institutions that were teaching homoeopathy.

However, it was not long after this period of time (in the early 1920’s) that many of the schools closed — mostly due to the decline of Homoeopathy’s popularity which was greatly effected by the American Medical Association (AMA). This was also around the time when modern drug companies began releasing drugs that were easy to administer to patients, a trend that also contributed to the decline of Homoeopathy.

Today, homoeopathy is also rising again in the United States. This resurgence has been documented by the National Center for Homoeopathy in Virginia, which stated that Americans spent 230 million dollars on homoeopathic remedies in 1996. It has also been said that sales are rising rapidly at about 12 – 15% each year. Doctors, scientists, researchers, corporations and the general public are all responsible for the accelerated expansion in the interest of homoeopathic products, research and educational initiatives. Reflecting its global resurgence, besides conventional drugs, homeopathic remedies are the only other system of official, regulated medicine in the USA.  Since patients under homeopathic care lived longer, some life insurance companies even offered a 10 per cent discount to homeopathic patients! 

Homeopathy, arguably the safest alternative medicine is making a strong global comeback, despite having lost the first round to allopathy. Although the United States experienced a dwindling interest in homoeopathy in the 20th century, many countries in Europe and Asia were experiencing a steady growth of homoeopathic teachings and interest. 

Homeopathy is most popular in the UK, where the Royal Family has had homeopathic physicians since the 1830s. In England, as many as 45 per cent of conventional MDs refer patients to homeopaths and the treatment is part of the National Health Scheme (NHS). Reveals Dr. Mukesh Batra: "The Queen Mother is now 100 years old, but wherever she goes, she takes here homeopathic kit. And she still walks upright although she has arthritis. Prince Charles told the British Medical Association that they were losing track of human beings and must be more humane in their treatment. So he's also for alternative medicine. In the past few years, homeopathy has become part of the National Health Scheme (NHS), which means that a patient can visit a homeopath and the government pays for the treatment. That hasn't happened even in India." 

In Asia too, the treatment is very popular—especially in India, Pakistan and Sri Lanka. Homeopathy benefited enormously through Mahatma Gandhi's statement: "Homeopathy is the latest, most refined method of treating patients economically and nonviolently. Government must encourage and patronize it in our country." Quaid-e-Azam Muhammad Ali Jinnah said "I am glad to learn that homoeopathic system is becoming quite popular, beside America and Europe, in all sections of population in the subcontinent"...."it is essential that those who want to take advantage of this economical and effective system should take interest in it".