Tea is, after water, the most widely consumed drink in the world. Roughly three billion cups are brewed every day, in cultures as different as Moroccan mint ceremonies, Japanese matcha rituals, the sweetened chai of India, and the simple builder’s brew of a British kitchen. Despite this enormous variety, every cup of true tea comes from the leaves of a single plant: Camellia sinensis, a hardy evergreen shrub native to the borderlands of southwest China, northern Burma and northeast India.

The story of how a wild leaf became a global drink stretches across nearly five thousand years and involves emperors, monks, merchants, smugglers and clipper ships racing each other across oceans.

Chinese legend attributes the discovery of tea to the Emperor Shen Nung in 2737 BCE. According to the story, the emperor was boiling water beneath a tree when a few leaves drifted into his pot. The resulting infusion was fragrant and refreshing, and tea was born. The story is almost certainly mythical, but archaeological evidence does confirm that tea was being consumed in China at least three thousand years ago, originally for its medicinal properties rather than as an everyday drink.

By the Tang dynasty in the seventh century, tea had become a cultural fixture. The poet and scholar Lu Yu wrote a celebrated work called The Classic of Tea around 760 CE, describing in elaborate detail how tea should be grown, prepared and appreciated. He was so revered for this work that tea merchants reportedly worshipped him as a kind of patron saint of their trade.

The Chinese drank their tea differently in those early centuries. Leaves were often compressed into bricks for trade and transport, then broken off, ground to powder, and whisked into hot water. The loose-leaf brewing familiar today only became widespread during the Ming dynasty in the fourteenth century, when an emperor decreed that tea should be served as whole leaves rather than as cakes.

Tea reached Japan in the eighth century, carried by Buddhist monks who had studied in China and brought seeds and the practice of tea-drinking home with them. It was initially a drink for monks and aristocrats, valued for its ability to keep one alert during long meditations.

Over the following centuries, Japanese tea culture evolved into something quite distinct from its Chinese origins. The tea ceremony, known as chanoyu, became a highly formalised practice combining hospitality, aesthetics and Zen philosophy. Matcha — the powdered green tea still used in these ceremonies today — became the central focus of an art form that prizes simplicity, attention and the appreciation of imperfection.

For most of its history, tea was unknown in Europe. The first Europeans to encounter it were Portuguese traders and Jesuit missionaries in the sixteenth century. The Dutch East India Company began importing it to Europe in the early 1600s, but it remained an expensive curiosity for several decades — sold by apothecaries as a health tonic rather than enjoyed as a daily drink.

Britain’s love affair with tea began in earnest in 1662, when Catherine of Braganza, a Portuguese princess accustomed to drinking tea at home, married King Charles II and brought the habit with her to the English court. The drink quickly became fashionable among the aristocracy, and from there it filtered down through society over the following century, helped by falling prices and the growing influence of the British East India Company.

The taxes Britain placed on imported tea also played an unexpected role in world history. Heavy duties on tea exported to the American colonies led to the famous Boston Tea Party of 1773, when colonists boarded ships in Boston Harbour and tipped 342 chests of tea into the sea in protest. That single act of defiance helped set in motion the American Revolution.

By the early nineteenth century, Britain was importing enormous quantities of tea from China, and balancing the trade was a constant difficulty. This contributed, regrettably, to the British smuggling of opium into China — and ultimately to the Opium Wars. It also drove a search for tea-growing regions outside Chinese control.

That search bore fruit in 1823, when a Scottish adventurer named Robert Bruce discovered that wild tea plants were growing in the Assam region of northeast India. Within two decades, British planters had established commercial tea estates there, breaking China’s centuries-old monopoly on the trade. Tea cultivation soon spread to Darjeeling, Ceylon (modern Sri Lanka), and later to parts of Africa.

The era also gave rise to the great tea clipper ships — fast, elegant sailing vessels built to race the new season’s tea from China and India back to London. The famous Cutty Sark, now preserved in dry dock in Greenwich, was built for precisely this purpose, and the annual races between rival ships were national events.

Today, tea is grown commercially in more than fifty countries, with China, India, Kenya and Sri Lanka the largest producers. The varieties most people know — black, green, white, oolong and pu-erh — all come from the same plant, distinguished only by how the leaves are processed after picking. Herbal “teas” such as peppermint or chamomile, although called tea, are technically infusions and contain no Camellia sinensis at all.

For something so commonplace, tea carries a remarkable amount of history in every cup. A pot brewed in a kitchen this afternoon connects the drinker, however faintly, to Tang dynasty scholars, Zen monks, Portuguese princesses, clipper-ship captains and Indian tea-pickers — a chain of small daily rituals reaching back across millennia.