Paleolithic
No fossil proven to be Homo erectus has been found in the Korean Peninsula, though a candidate has been reported. Tool-making artifacts from the Palaeolithic period have been found in present-day North Hamgyong, South Pyongan, Gyeonggi, and north and south Chungcheong Provinces of Korea, which dates the Paleolithic Age to half a million years ago, though it may have begun as late as 400,000 years ago or as early as 600,000–700,000 years ago.
Neolithic
The earliest known Korean pottery dates back to around 8000 BCE, and evidence of Mesolithic Pit–Comb Ware culture (or Yunggimun pottery) is found throughout the peninsula, such as in Jeju Island. Jeulmun pottery, or "comb-pattern pottery", is found after 7000 BCE, and is concentrated at sites in west-central regions of the Korean Peninsula, where a number of prehistoric settlements, such as Amsa-dong, existed. Jeulmun pottery bears basic design and form similarities to that of Mongolia, the Amur and Sungari river basins of Manchuria, the Jōmon culture in Japan, and the Baiyue in Southern China and Southeast Asia.
Archaeological evidence demonstrates that agricultural societies and the earliest forms of social-political complexity emerged in the Mumun pottery period (c. 1500–300 BCE).
People in southern Korea adopted intensive dry-field and paddy-field agriculture with a multitude of crops in the Early Mumun Period (1500–850 BCE). The first societies led by big-men or chiefs emerged in the Middle Mumun (850–550 BC), and the first ostentatious elite burials can be traced to the Late Mumun (c. 550–300 BCE). Bronze production began in the Middle Mumun and became increasingly important in ceremonial and political society after 700 BCE. Archeological evidence from Songguk-ri, Daepyeong, Igeum-dong, and elsewhere indicate that the Mumun era was the first in which chiefdoms rose, expanded, and collapsed. The increasing presence of long-distance trade, an increase in local conflicts, and the introduction of bronze and iron metallurgy are trends denoting the end of the Mumun around 300 BCE.
In addition, 73 tombs similar to the ones found in Japan, estimated to date back to Gojoseon (100 B.C.), have been found in the southern tip of the Korean peninsula, and the discovery of jar burials, suggest a close relationship with Japan, and Gojoseon, proving that Gojoseon and Yayoi period Japan maintained close relations with one another even during the ancient times.
Gojoseon, Chinese Rule and Jin state
Gojoseon was the first Korean kingdom, located in the north of the peninsula and Manchuria, later alongside the state of Jin in the south of the peninsula.
The founding legend of Gojoseon, which is recorded in the Samguk Yusa (1281) and other medieval Korean books, states that the country was established in 2333 BCE by Dangun, said to be descended from heaven. While no evidence has been found that supports whatever facts may lie beneath this, the account has played an important role in developing Korean national identity. In the 12th century BCE, Gija, a prince from the Shang dynasty of China, purportedly founded Gija Joseon. However, due to contradicting historical and archaeological evidence, its existence was challenged in the 20th century, and today no longer forms the mainstream understanding of this period.
The historical Gojoseon kingdom was first mentioned in Chinese records in the early 7th century BCE. By about the 4th century BCE, Gojoseon had developed to the point where its existence was well known in China, and around this time, its capital moved to Pyongyang.
In 195 BCE, Jun of Gojoseon appointed a refugee from Yan, Wiman. Wiman later rebelled in 194 BCE, and Jun fled to the south of the Korean Peninsula.
Chinese Rule
In 108 BCE, the Chinese Han dynasty defeated Wiman Joseon and installed four commanderies in the northern Korean peninsula. Three of the commanderies fell or retreated westward within a few decades, but the Lelang commandery remained as a center of cultural and economic exchange with successive Chinese dynasties for four centuries, until it was conquered by Goguryeo in 313 AD.
Jin State
Around 300 BCE, a state called Jin arose in the southern part of the Korean peninsula. Very little is known about Jin, but it established relations with Han China and exported artifacts to the Yayoi of Japan. Around 100 BCE, Jin evolved into the Samhan confederacies.
Many smaller states sprang from the former territory of Gojoseon such as Buyeo, Okjeo, Dongye, Goguryeo, and Baekje. The Three Kingdoms refer to Goguryeo, Baekje, and Silla, although Buyeo and the Gaya confederacy existed into the 5th and 6th centuries respectively.
Metallurgy
The Bronze Age is often held to have begun around 900-800 BCE in Korea, though the transition to the Bronze Age may have begun as far back as 2300 BCE. Bronze daggers, mirrors, jewelry, and weaponry have been found, as well as evidence of walled-town polities. Rice, red beans, soybeans and millet were cultivated, and rectangular pit-houses and increasingly larger dolmen burial sites are found throughout the peninsula. Contemporaneous records suggest that Gojoseon transitioned from a feudal federation of walled cities into a centralised kingdom at least before the 4th-century BCE. It is believed that by the 4th century BCE, iron culture was developing in Korea by northern influence via today's Russia's Maritime Province.
Proto–Three Kingdoms
The Proto-Three Kingdoms period, sometimes called the Several States Period (열국시대), is the time before the rise of the Three Kingdoms of Korea, which included Goguryeo, Silla, and Baekje, and occurred after the fall of Gojoseon. This time period consisted of numerous states that sprang up from the former territories of Gojoseon. Among these states, the largest and most influential were Dongbuyeo and Bukbuyeo.
Buyeo and other Northern states
After the fall of Gojoseon, Buyeo arose in today's North Korea and southern Manchuria, from about the 2nd century BCE to 494. Its remnants were absorbed by Goguryeo in 494, and both Goguryeo and Baekje, two of the Three Kingdoms of Korea, considered themselves its successor.
Although records are sparse and contradictory, it is thought that in 86 BCE, Dongbuyeo (East Buyeo) branched out, after which the original Buyeo is sometimes referred to as Bukbuyeo (North Buyeo). Jolbon Buyeo was the predecessor to Goguryeo, and in 538, Baekje renamed itself Nambuyeo (South Buyeo).
Okjeo was a tribal-state that was located in the northern Korean Peninsula, and was established after the fall of Gojoseon. Okjeo had been a part of Gojoseon before its fall. It never became a fully developed kingdom due to the intervention of its neighboring kingdoms. Okjeo became a tributary of Goguryeo, and was eventually annexed into Goguryeo by Gwanggaeto Taewang in the 5th century.
Dongye was another small kingdom that was situated in the northern Korean Peninsula. Dongye bordered Okjeo, and the two kingdoms faced the same fate of becoming tributaries of the growing empire of Goguryeo. Dongye was also a former part of Gojoseon before its fall.
Samhan
Sam-han (삼한, 三韓) refers to the three confederacies of Mahan, Jinhan, and Byeonhan. The Samhan were located in the southern region of the Korean Peninsula. The Samhan countries were strictly governed by law, with religion playing an important role. Mahan was the largest, consisting of 54 states, and assumed political, economic, and cultural dominance. Byeonhan and Jinhan both consisted of 12 states, bringing a total of 78 states within the Samhan. The Samhan were eventually conquered by Baekje, Silla, and Gaya in the 4th century.