Muhammad was born around 570 CE in Mecca, a religious centre of polytheistic faiths in the Middle East. Muhammad became a successful trader, and during his trading trips, he encountered members of monotheistic religions, Jews and Christians, and became very fond of their word. When Muhammad was in his forties, he began claiming that he was the last prophet God had chosen to deliver His divine message. Muhammad preached and gained a large following, particularly among the poor, converting many polytheistic tribes in the Middle East to monotheism. Yet, as both already existing monotheistic faiths saw Muhammad as no more than a heretical lunatic, the world today has three monotheistic religions – Judaism, Christianity, and Islam – which basically worship the same omnipotent, but have different religious doctrines.
Islam is the second-largest religion today. Its doctrine resides in the Qur'an, a holy book of Muslims that contains the message Muhammad claimed to have received from the angel Gabriel in a cave near Mecca. The Islamic calendar begins in 622 CE, when Muhammad and his followers fled Mecca after angering the established polytheistic elite, and settled in Medina, which accepted Muhammad and his teachings. Years later, Muhammad returned with an army and took the city under Muslim rule. Muhammad died in 632 CE, and soon after, Islam split into two sects, Sunnis and Shias, over a dispute of succession. However, this did not stop Islam from spreading. Within a hundred years, Muhammad's followers had conquered not only the Arabian Peninsula but also large areas in Africa and Asia, and parts of Europe, in the name of Allah.
Throughout history, the world has seen multiple numeral systems, many of which have been very ill-suited even for the most straightforward calculations. Yet, the numerals we use today, 0 1 2 3 4 5 6 7 8 9, are so few and simple, and the ways we can use them in mathematics as well as to write numbers are so convenient, that we tend to take them for granted. These ten signs have roots in India in the first millennium BCE and were completed in 628 CE, when the Indian mathematician Brahmagupta formalised zero (nothing) as a number and stated the rules for its use in calculations. In the eighth or ninth century CE, the expanding Muslim empires encountered the numerals, realised their usefulness, and began to refine and spread them across the Middle East (hence the name Hindu-Arabic), before reluctant Europeans came to understand their superiority over Roman numerals in the fourteenth century CE.
During the 8th and 13th centuries, the Islamic world thrived under the Abbasid Caliphate. Whilst Christianity killed curiosity towards knowledge and learning in Europe, other than that of a religious nature, scholars in the Abbasid Caliphate were gathering information from around the world, translating it into Arabic, and using the materials to make advances in subjects such as mathematics, medicine, astronomy, and many others.
Somewhere in the mid-ninth century CE, a Chinese alchemist was searching for an elixir of life, but instead found a mixture to sow death and devastation. By mixing saltpetre, charcoal, and sulfur, he created gunpowder, and it didn't take long for gunpowder to be harnessed for military purposes in the form of fire lances. However, the first real guns appeared in China by the end of the thirteenth century, with the Arabs and Europeans only a few decades behind.
While many are familiar with the Renaissance in Europe, fewer may know that China experienced its own information upheaval hundreds of years before under the Song dynasty. The nation's population grew rapidly due to advances made in rice farming, and many of its cities were home to more than a million people, whose better-off parts could enjoy themselves with, for example, a wide variety of restaurants, theatres, and mass-printed books. Literacy rates grew, family businesses thrived, and products and services could be paid for with the first paper currency. Besides, Song China can be seen as the first modernly run state, as its operations were managed by highly educated officials rather than the dictator’s relatives and closest circle. Eventually, Song China was overrun by the Mongols, who came to rule the largest contiguous land empire the world has ever seen.
Humans have been travelling on water for tens of thousands of years, first using simple rafts, canoes, and boats, before developing wind-powered ships that enabled longer voyages. Early seafarers navigated across the seas with the help of the sun and stars, but finding and keeping the right direction was extremely difficult and weather-dependent before the compass was invented in China. Compass has roots in the third century BCE, but for a long time it was used in Feng Shui (a form of decoration intended to achieve harmony and fortune) rather than for navigation. It was not until the eleventh century CE that the Chinese utilised the compass in navigation at sea.
Since the day Christianity began spreading across the world, the Christian Church has faced difficulties maintaining unity because of its incoherent doctrine. Nevertheless, the Church remained officially as one for the first thousand or so years. But during the time, tensions and disagreements had risen, especially between the bishops of two great cities, Rome and Constantinople, both claiming authority over the bishops of lesser cities. Eventually, in 1054 CE, the power struggle between the bishop of Rome (the pope) and the bishop of Constantinople (the patriarch) resulted in a split into the Western Catholic and Eastern Orthodox Churches – an event known as the Great Schism. A few hundred years later, the Catholic Church split further, giving rise to Protestantism, the third major branch of Christianity today.
The Black Death is often regarded as the worst pandemic in human history, as bubonic plague sowed death in Eurasia and Africa in 1346-1351. It killed more than half of those infected within just a matter of days, causing also black bags of pus and blood that made the disease as visually terrifying as it was lethal. The scourge hit Europe especially hard, with modest estimates suggesting that one-third of the population vanished. As devastating as the Black Death was, it pushed Europe, which had been overcrowded and stagnant through the Middle Ages, to change, and laid the foundations for its rise to rule the world in the following centuries.