Joseon (English: /ˈtʃoʊsʌn/ CHOH-sun; Korean: 조선; Hanja: 朝鮮; MR: Chosŏn; pronounced [tɕo.sʰʌn]; also romanized as Chosun), officially Great Joseon (대조선국; 大朝鮮國; [tʰɛ.dʑo.sʰʌn.ɡuk̚]), was a dynastic kingdom of Korea that existed for 505 years. It was founded by Taejo of Joseon in July 1392 and replaced by the Korean Empire in October 1897. The kingdom was founded after the overthrow of Goryeo in what is today the city of Kaesong. Early on, Korea was retitled and the capital was moved to modern-day Seoul. The kingdom's northernmost borders were expanded to the natural boundaries at the rivers of Amnok and Tuman through the subjugation of the Jurchens.

Over the centuries, Joseon encouraged the entrenchment of Confucian ideals and doctrines in Korean society. Neo-Confucianism was installed as the new state's ideology. Buddhism was accordingly discouraged, and occasionally Buddhists faced persecution. Joseon consolidated its effective rule over the Korean peninsula and saw the height of classical Korean culture, trade, literature, and science and technology. The kingdom was severely weakened by failed Japanese invasions in 1592 and 1598, which were followed by invasions by the Later Jin dynasty in 1627 and the Qing dynasty in 1636–1637. The country pursued an increasingly harsh isolationist policy, becoming known as the "hermit kingdom" in Western literature. After the end of these invasions from Manchuria, Joseon experienced a nearly 200-year period of peace and prosperity, along with cultural and technological development. What power the kingdom recovered during its isolation waned as the 18th century came to a close. Faced with internal strife, power struggles, international pressure, and rebellions at home, the kingdom declined rapidly in the late 19th century.

The Joseon period left a substantial legacy. Modern Korean bureaucracy and administrative divisions were established during it. The modern Korean language and its dialects derive from the culture and traditions of Joseon, as does much of Korean culture, etiquette, norms, and societal attitudes.

By the late 14th century, the nearly 500-year-old Goryeo established in 918 was tottering, its foundations collapsing from years of war spilled over from the disintegrating Yuan dynasty. Following the emergence of the Ming dynasty, the royal court in Goryeo split into two conflicting factions, one favoring neutrality and the other wanting to retake the Liaodong peninsula, which many in Goryeo believed was theirs. Goryeo remained a neutral third-party observer in the conflict between the Yuan and the Ming and had friendly diplomatic relations with both. In 1388, a Ming messenger came to Goryeo to demand that territories of the former Ssangseong Prefecture be handed over to Ming China. The tract of land was taken by Mongol forces during the invasion of Korea, but had been reclaimed by Goryeo in 1356 as the Yuan dynasty weakened. The act caused an uproar among the Goryeo court, and General Ch'oe Yŏng seized the chance to argue for an invasion of the Ming-controlled Liaodong Peninsula.

General Yi Sŏnggye was chosen to lead the attack; he revolted, swept back to the capital Kaegyŏng (now Kaesong) and initiated a coup d'état, overthrowing King U of Goryeo in favor of his son, Chang of Goryeo (1388). Neo-Confucian scholars, who were a small and medium-sized power at the time, were able to use this incident as an opportunity to lay a political foundation, and in particular, Chŏng Tojŏn, a friend of Yi Sŏnggye, wanted to use this incident as an opportunity to reform the corrupt nobles and the Buddhist community. He later killed King U and his son after a failed restoration and forcibly placed a royal named Wang Yo on the throne (he became King Gongyang of Goryeo). In 1392, Yi eliminated Chŏng Mong-ju, a highly respected leader of a group loyal to the Goryeo dynasty, and dethroned King Gongyang, exiling him to Wonju, and he ascended the throne himself. The Goryeo kingdom had come to an end after 474 years of rule.

At the beginning of his reign, Yi Sŏnggye, now ruler of Korea, intended to continue to use the name Goryeo for the country he ruled and simply change the royal line of descent to his own, thus maintaining the façade of continuing the 500-year-old Goryeo tradition. After numerous threats of mutiny from the drastically weakened but still influential Gwonmun nobles, who continued to swear allegiance to the remnants of the Goryeo and to the now-demoted House of Wang, the consensus in the reformed court was that a new dynastic title was needed to signify the change. In naming the new kingdom, Taejo contemplated two possibilities – "Hwaryeong" (his place of birth) and "Joseon". After much internal deliberation, as well as endorsement by the neighboring Ming dynasty's emperor, Taejo declared the name of the kingdom to be Joseon, a tribute to the ancient Korean state of Gojoseon. He also moved the capital to Hanseong (modern Seoul) from Kaegyŏng (modern Kaesong).

When the new dynasty was brought into existence, Taejo brought up the issue of which son would be his successor. Although Yi Pangwŏn, Taejo's fifth son by Queen Sinui, had contributed the most to assisting his father's rise to power, Chief State Councillor Chŏng Tojŏn and Nam Ŭn used their influence on the king to name Yi Pangsŏk, his eighth son (second son of Queen Sindeok), as crown prince in 1392. This conflict arose largely because Chŏng Tojŏn, who shaped and laid down ideological, institutional, and legal foundations of the new kingdom more than anyone else, saw Joseon as a kingdom led by ministers appointed by the king while Yi Bang-won wanted to establish an absolute monarchy ruled directly by the king. With Taejo's support, Chŏng Tojŏn kept limiting the royal family's power by prohibiting the political involvement of princes and attempting to abolish their private armies. Both sides were well aware of each other's great animosity and were getting ready to strike first.

After the sudden death of Queen Sindeok, while King Taejo was still in mourning for his second wife, Yi Pangwŏn struck first by raiding the palace and killed Chŏng Tojŏn and his supporters as well as Queen Sindeok's two sons (his half-brothers) including the crown prince in 1398. This incident became known as the "First Strife of Princes".