Great Wall of China in the context of "Aisin Gioro"

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.

Stonemasonry or stonecraft is the creation of buildings, structures, and sculpture using stone as the primary material. Stonemasonry is the craft of shaping and arranging stones, often together with mortar and even the ancient lime mortar, to wall or cover formed structures.

The basic tools, methods and skills of the banker mason have existed as a trade for thousands of years. It is one of the oldest activities and professions in human history. Many of the long-lasting, ancient shelters, temples, monuments, artifacts, fortifications, roads, bridges, and entire cities were built of stone. Famous works of stonemasonry include Göbekli Tepe, the Egyptian pyramids, the Taj Mahal, Cusco's Incan Wall, Taqwesan, Easter Island's statues, Angkor Wat, Borobudur, Tihuanaco, Tenochtitlan, Persepolis, the Parthenon, Stonehenge, the Great Wall of China, the Mesoamerican pyramids, Chartres Cathedral, and the Stari Most.

A defensive wall is a fortification usually used to protect a city, town or other settlement from potential aggressors. The walls can range from simple palisades or earthworks to extensive military fortifications such as curtain walls with towers, bastions and gates for access to the city. From ancient to modern times, they were used to enclose settlements. Generally, these are referred to as city walls or town walls, although there were also walls, such as the Great Wall of China, Walls of Benin, Hadrian's Wall, Anastasian Wall, and the Atlantic Wall, which extended far beyond the borders of a city and were used to enclose regions or mark territorial boundaries. In mountainous terrain, defensive walls such as letzis were used in combination with castles to seal valleys from potential attack. Beyond their defensive utility, many walls also had important symbolic functions – representing the status and independence of the communities they embraced.

Existing ancient walls are almost always masonry structures, although brick and timber-built variants are also known. Depending on the topography of the area surrounding the city or the settlement the wall is intended to protect, elements of the terrain such as rivers or coastlines may be incorporated in order to make the wall more effective.

A border barrier, border fence or border wall is a separation barrier that runs along or near an international border. Such barriers are typically constructed for border control purposes such as curbing illegal immigration, human trafficking, and smuggling. Some such barriers are constructed for defence or security reasons. In cases of a disputed or unclear border, erecting a barrier can serve as a de facto unilateral consolidation of a territorial claim that can supersede formal delimitation. A border barrier does not usually indicate the location of the actual border, and is usually constructed unilaterally by a country, without the agreement or cooperation of the other country.

Examples of border walls include the ancient Great Wall of China, a series of walls separating China from nomadic empires to the north. The construction of border barriers increased in the early 2000s; half of all the border barriers built since World War II, which ended in 1945, were built after 2000.

Khanbaliq (Chinese: 汗八里; pinyin: Hánbālǐ; Mongolian: ᠬᠠᠭᠠᠨ ᠪᠠᠯᠭᠠᠰᠤ, Qaɣan balɣasu) or Dadu (Chinese: 元大都; pinyin: Yuán Dàdū; Mongolian: ᠳᠠᠶ᠋ᠢᠳᠤ, Dayidu) was the winter capital of the Mongol-led Yuan dynasty in what is now Beijing, the capital of China today. It was located at the center of modern Beijing. The Secretariat directly administered the Central Region (腹裏) of the Yuan dynasty (comprising present-day Beijing, Hebei, Shandong, Shanxi, and parts of Henan and Inner Mongolia) and dictated policies for the other provinces. As emperors of the Yuan dynasty, Kublai Khan and his successors also claimed supremacy over the entire Mongol Empire following the death of Möngke (Kublai's brother and predecessor) in 1259. Over time the unified empire gradually fragmented into a number of khanates.

Khanbaliq is the direct predecessor to modern Beijing. Several stations of the modern city's subway's Line 10 and Line 13 are named after the gates of Dadu.

The Dzungar Khanate (Mongolian: ᠵᠡᠭᠦᠨᠭᠠᠷ ᠣᠯᠣᠰ Зүүнгар Улс), also known as the Zunghar Khanate or Junggar Khanate, was a nomadic khanate of Oirat Mongol origin. At its greatest extent, it covered an area from southern Siberia in the north to present-day Kyrgyzstan in the south, and from present-day west of Mongolia and the Great Wall of China in the east to present-day Kazakhstan in the west. The core of the Dzungar Khanate is today part of northern Xinjiang, also called Dzungaria.

About 1620 the western Mongols, known as the Oirats, united in the Junggar Basin in Dzungaria. In 1678, Galdan received from the Dalai Lama the title of Boshogtu Khan, making the Dzungars the leading tribe within the Oirats. The Dzungar rulers used the title of Khong Tayiji, which translates into English as "crown prince". Between 1680 and 1688, the Dzungars conquered the Tarim Basin, which is now southern Xinjiang, and defeated the Khalkha Mongols to the east. In 1696, Galdan was defeated by the Qing dynasty and lost Outer Mongolia. In 1717, the Dzungars conquered Tibet, but were driven out in 1720 by the Qing. From 1755 to 1758, Qing China took advantage of a Dzungar civil war to conquer Dzungaria and killed 70–80% of the Dzungar population. The destruction of the Dzungars led to the Qing conquest of Mongolia, Tibet, and the creation of Xinjiang as a political administrative unit.

The House of Aisin-Gioro is a Manchu clan that ruled the Later Jin dynasty (1616–1636), the Qing dynasty (1636–1912), and Manchukuo (1932–1945) in the history of China. Under the Ming dynasty, members of the Aisin Gioro clan served as chiefs of the Jianzhou Jurchens, one of the three major Jurchen tribes at this time. Qing bannermen passed through the gates of the Great Wall in 1644, and eventually conquered the short-lived Shun dynasty, Xi dynasty and Southern Ming dynasty. After gaining total control of China proper, the Qing dynasty later expanded into other adjacent regions, including Xinjiang, Tibet, Outer Mongolia, and Taiwan. The dynasty reached its zenith during the High Qing era and under the Qianlong Emperor, who reigned from 1735 to 1796. This reign was followed by a century of gradual decline.

The house lost power in 1912 following the Xinhai Revolution. Puyi, the last Aisin-Gioro emperor, nominally maintained his imperial title in the Forbidden City until the Articles of Favourable Treatment were revoked by Feng Yuxiang in 1924. The Qing was China's last orthodox imperial dynasty.

The Shanhai Pass (simplified Chinese: 山海关; traditional Chinese: 山海關; pinyin: Shānhǎi Guān; lit. 'Mountain Sea Pass') is a major fortified gateway at the eastern end of the Great Wall of China and one of its most crucial fortifications, as the pass commands the narrowest choke point in the strategic Liaoxi Corridor, an elongated coastal plain between the Yan Mountains foothills and the Bohai Sea, which is the only easily traversable landway between North and Northeast China. It is located in present-day Shanhaiguan District, Qinhuangdao, Hebei province, on the east bank of the Shi River, with defensive walls stretching from the Yan Mountains all the way to the shores of the Liaodong Bay.

Throughout Chinese history, garrisons around the pass served as frontline defensive outposts against raids and incursions into the North China Plain by various non-Sinitic ethnic groups from the Northeast (also known as Manchuria since the 19th century), including the Dongyi, Donghu (Xianbei and Wuhuan), Khitan and Jurchen (Manchus). The current Shanhai Pass was built during the early Ming dynasty as the easternmost fortification of the Ming Great Wall, and was extensively reinforced after Yongle Emperor moved the capital from Nanjing to Beijing following the Jingnan campaign, making it the most important defensive barrier in all of China, as it shielded the heartland region around the imperial capital. The pass' strategic location dictated that without mounting a costly direct siege, the only way an invading army can get past the pass' defense was to circumvent it around the north through a few treacherously narrow mountain passes deep within the Yan Mountains, which would make it very difficult to maintain supply lines and thus any sizeable invasions. This defensive significance therefore earned the pass the famous nickname "Greatest Pass Under Heaven" (天下第一关).