Gunpowder in the context of "Solid rocket motor"

Human history or world history is the record of humankind from prehistory to the present. Modern humans evolved in Africa around 300,000 years ago and initially lived as hunter-gatherers. They migrated out of Africa during the Last Ice Age and had spread to every continent except Antarctica by the end of the Ice Age 12,000 years ago. Soon afterward, the Neolithic Revolution in West Asia brought the first systematic husbandry of plants and animals, and saw many humans transition from nomadic lives to sedentary existences as farmers in permanent settlements. The growing complexity of human societies necessitated systems of accounting and writing.

These developments paved the way for the emergence of early civilizations in Mesopotamia, Egypt, Peru, the Indus Valley, and China, marking the beginning of the ancient period in the 4th millenium BCE. These civilizations enabled the establishment of regional empires and provided fertile ground for the advent of transformative philosophical and religious ideas. Hinduism originated during the late Bronze Age and was followed by the many seminal belief systems of the Axial Age: Buddhism, Confucianism, Greek philosophy, Jainism, Judaism, Taoism, and Zoroastrianism. Christianity began later as an offshoot of Judaism. The subsequent post-classical period, from about 500 to 1500 CE, witnessed the rise of Islam and China's flourishing under the Tang and Song dynasties while civilization expanded to new parts of the world and trade between societies increased. The political landscape was shaped by the rise and fall of major empires, such as the Byzantine Empire, the Islamic caliphates, and the Mongol Empire. This period's invention of gunpowder and the printing press greatly affected later history.

Ancient Chinese scientists and engineers made significant scientific innovations, findings and technological advances across various scientific disciplines including the natural sciences, engineering, medicine, military technology, mathematics, geology and astronomy.

Among the earliest inventions were the abacus, the sundial, and the Kongming lantern. The Four Great Inventions – the compass, gunpowder, papermaking, and printing – were among the most important technological advances, only known to Europe by the end of the Middle Ages 1000 years later. The Tang dynasty (AD 618–906) in particular was a time of great innovation. A good deal of exchange occurred between Western and Chinese discoveries up to the Qing dynasty.

In world history, post-classical history refers to the period from about 500 CE to about 1450 or 1500 CE, roughly corresponding to the European Middle Ages following the decline of the western Roman Empire. The post-classical period is characterized by the expansion of certain civilizations geographically, by ongoing wars fought over land, resources and religion, and by the development of trade networks between often-distant civilizations. This period is also called—with various implications and emphases—the medieval era, the post-antiquity era, the post-ancient era, or the pre-modern era.

In Asia and the Middle East during this time, the spread of Islam helped produce a series of caliphates which fostered the Islamic Golden Age, leading to advances in science and greater trade between those in the Asian, African, and European continents. East Asia experienced the entrenchment of the power of a unitary and Imperial China, the dynastic governance and culture of which influenced Japan, Korea and Vietnam. Religions such as Buddhism and neo-Confucianism spread in the region, while Christianity became entrenched in Europe and increasingly elsewhere. Gunpowder was developed in China during the post-classical era. The Mongol Empire conquered and controlled much of Europe and Asia, permitting more trade and cultural and intellectual exchange between the two regions.

A siege engine is a device that is designed to break or circumvent heavy castle doors, thick city walls and other fortifications in siege warfare. Some are immobile, constructed in place to attack enemy fortifications from a distance, while others have wheels to enable advancing up to the enemy fortification. There are many distinct types, such as siege towers that allow foot soldiers to scale walls and attack the defenders, battering rams that damage walls or gates, and large ranged weapons (such as ballistas, catapults/trebuchets and other similar constructions) that attack from a distance by launching heavy projectiles. Some complex siege engines were combinations of these types.

Siege engines are fairly large constructions – from the size of a small house to a large building. From antiquity up to the development of gunpowder, they were made largely of wood, using rope or leather to help bind them, possibly with a few pieces of metal at key stress points. They could launch simple projectiles using natural materials to build up force by tension, torsion, or, in the case of trebuchets, human power or counterweights coupled with mechanical advantage. With the development of gunpowder and improved metallurgy, bombards and later heavy artillery became the primary siege engines.

The walls of Constantinople (Turkish: Konstantinopolis Surları; Greek: Τείχη της Κωνσταντινούπολης) are a series of defensive stone walls that have surrounded and protected the city of Constantinople (modern Fatih district of Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built.

Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger. They saved the city, and the Byzantine Empire with it, during sieges by the Avar–Sassanian coalition, Arabs, Rus', and Bulgars, among others. The fortifications retained their usefulness even after the advent of gunpowder siege cannons, which played a part in the city's fall to Ottoman forces in 1453 but were not able to breach its walls.

China has been the source of many innovations, scientific discoveries and inventions. This includes the Four Great Inventions: papermaking, the compass, gunpowder, and early printing (both woodblock and movable type). The list below contains these and other inventions in ancient and modern China attested by archaeological or historical evidence, including prehistoric inventions of Neolithic and early Bronze Age China.

The historical region now known as China experienced a history involving mechanics, hydraulics and mathematics applied to horology, metallurgy, astronomy, agriculture, engineering, music theory, craftsmanship, naval architecture and warfare. Use of the plow during the Neolithic period Longshan culture (c. 3000 – c. 2000 BC) allowed for high agricultural production yields and rise of Chinese civilization during the Shang dynasty (c. 1600 – c. 1050 BC). Later inventions such as the multiple-tube seed drill and the heavy moldboard iron plow enabled China to sustain a much larger population through improvements in agricultural output.

The Silk Road was a network of Asian trade routes active from the second century BCE until the mid-15th century. Spanning over 6,400 km (4,000 mi) on land, it played a central role in facilitating economic, cultural, political, and religious interactions between the Eastern and Western worlds. The name "Silk Road" was coined in the late 19th century, but some 20th- and 21st-century historians instead prefer the term Silk Routes, on the grounds that it more accurately describes the intricate web of land and sea routes connecting Central, East, South, Southeast, and West Asia as well as East Africa and Southern Europe. In fact, some scholars criticise or even dismiss the idea of silk roads and call for a new definition or alternate term. According to them, the literature using this term has "privileged the sedentary and literate empires at either end of Eurasia" thereby ignoring the contributions of steppe nomads. In addition, the classic definition sidelines civilisations like India and Iran.

The Silk Road derives its name from the highly lucrative trade of silk textiles that were primarily produced in China. The network began with the expansion of the Han dynasty (202 BCE – 220 CE) into Central Asia around 114 BCE, through the missions and explorations of the Chinese imperial envoy Zhang Qian, which brought the region under unified control. The Chinese took great interest in the security of their trade products, and extended the Great Wall of China to ensure the protection of the trade route. The Parthian Empire provided a vital bridge connecting the network to the Mediterranean. Meanwhile, the rise of the Roman Empire in the west further established the western terminus of the interconnected trade system. By the first century CE, Chinese silk was widely sought after in Rome, Egypt, and Greece. Other lucrative commodities from the East included tea, dyes, perfumes, and porcelain; among Western exports were horses, camels, honey, wine, and gold. Aside from generating substantial wealth for emerging mercantile classes, the proliferation of goods such as paper and gunpowder greatly affected the trajectory of political history in several theatres in Eurasia and beyond.