The People's Republic of China was proclaimed by Mao Zedong, the chairman of the Chinese Communist Party (CCP), on October 1, 1949, in Tiananmen Square in Beijing. The government of a new state under the CCP, formally called the Central People's Government, was proclaimed by Mao at the ceremony, which marked the foundation of contemporary China.

The National Liberation Day of Korea is a public holiday celebrated annually on 15 August in both North Korea and South Korea. It commemorates the day when the Korean Peninsula was liberated by the Allies in 1945 from 35 years of Japanese colonial rule. The day also coincides with the anniversary of the establishment of the South Korean government in 1948. Liberation Day is the only political holiday that is celebrated in both Koreas.

The Chinese Civil War was fought between the government of the Republic of China (ROC), led by the Kuomintang (KMT), and the Chinese Communist Party (CCP). Armed conflict continued intermittently from 1 August 1927 until Communist victory that led to the Kuomintang's retreat to Taiwan on 7 December 1949.

The Second Sino-Japanese War was fought between the Republic of China and the Empire of Japan and its puppet states between 1937 and 1945, following a period of conflict localized to Manchuria that started in 1931. It is often regarded as the beginning of World War II in Asia, as the wars became heavily intertwined after Japan attacked the United States. It was the largest Asian war in the 20th century.

The Korean War was an armed conflict fought on the Korean Peninsula between North Korea and South Korea and their allies. North Korea was supported by China and the Soviet Union, while South Korea was supported by the United Nations led by the United States under the auspices of the United Nations Command (UNC).

On 6 and 9 August 1945, the United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki, respectively, during the final days of World War II. The aerial bombings killed 150,000 to 246,000 people, most of whom were civilians, and remain the first and only uses of nuclear weapons in an armed conflict.

The Nanjing Massacre or the Rape of Nanjing was the mass rape and murder, between December 1937 and March 1938, of Chinese civilians, noncombatants, and prisoners of war by the Imperial Japanese Army in Nanjing, the capital of the Republic of China. It took place immediately after the Battle of Nanjing and retreat of the National Revolutionary Army during the Second Sino-Japanese War.

The First Republic of Korea, officially the Republic of Korea, was the government of South Korea from August 1948 to June 1960. The First Republic was founded on 15 August 1948, and it became the first independent republican government in Korea. Syngman Rhee was the first president of South Korea. The National Assembly was created following the May 1948 general election, and the National Assembly in Seoul promulgated South Korea's first constitution in July, establishing a presidential system of government.

The surrender of the Empire of Japan in World War II was announced by Emperor Hirohito on 15 August and formally signed on 2 September 1945, ending the war. By the end of July 1945, the Imperial Japanese Navy (IJN) was incapable of conducting major operations and an Allied invasion of Japan was imminent. Together with the United Kingdom and China, the United States called for the unconditional surrender of Japan in the Potsdam Declaration on 26 July 1945—the alternative being "prompt and utter destruction".

The Jeju uprising was an uprising on Jeju Island, South Korea, from April 1948 to May 1949.

The Battle of Okinawa, codenamed Operation Iceberg, was a major battle of the Pacific War fought on the island of Okinawa by the United States Army and United States Marine Corps forces against the Imperial Japanese Army. The initial invasion of Okinawa on 1 April 1945 was the largest amphibious assault in the Pacific Theater of World War II. The Kerama Islands surrounding Okinawa were preemptively captured on 26 March 1945 by the U.S. Army 77th Infantry Division. The 82-day battle on Okinawa lasted from 1 April 1945 until 22 June 1945. After a long campaign of island hopping, the Allies were planning to use Kadena Air Base on the island as a staging point for Operation Downfall, the planned invasion of the Japanese home islands, 340 mi (550 km) away.

The Indian Independence Act 1947 is an act of the Parliament of the United Kingdom that partitioned British India into the two new independent dominions of India and Pakistan. On 15 July 1947 the House of Commons voted for the bill and the House of Lords gave its consent on the next day. The act received Royal Assent on 18 July 1947 and thus India and Pakistan came into being on 15 August.

The Long March was a military retreat by the Chinese Communist Party (CCP) and Chinese Red Army from advancing Kuomintang (KMT) National Revolutionary Army during the Chinese Civil War, occurring between October 1934 and October 1935. About 100,000 troops retreated from the Jiangxi Soviet and other bases to a new headquarters in Yan'an, Shaanxi, travelling approximately 10,000 kilometres. About 8,000 troops ultimately survived the Long March.

Singapore was captured from the British by the Empire of Japan in February 1942 during the Second World War. The Fall or Battle of Singapore took place in the South–East Asian theatre of the Pacific War, with fighting lasting from 8 to 15 February 1942. Singapore was the foremost British military base and economic port in South–East Asia and had been of great importance to British interwar defence strategy. The capture of Singapore was therefore a major loss for Britain and resulted in its largest surrender in history.

The Battle of Leyte Gulf was the largest naval battle of World War II and by some criteria the largest naval battle in history, with over 200,000 naval personnel involved.

The Proclamation of Indonesian Independence was read at 10:00 Tokyo Standard Time on Friday, 17 August 1945 in Jakarta. The declaration marked the start of the diplomatic and armed resistance of the Indonesian National Revolution, fighting against the forces of the Netherlands and pro-Dutch civilians, until the latter officially acknowledged Indonesia's independence in 1949. The document was signed by Sukarno and Mohammad Hatta, who were appointed president and vice-president respectively the following day.

The RDS-1, also known as First Lightning, was the first nuclear weapons test that was conducted by the Soviet Union. It was detonated on 29 August 1949 at 7:00 a.m. Kazakhstan Time (UTC+06:00), at the Semipalatinsk Test Site in the Kazakh Soviet Socialist Republic, and yielded 22 kilotons of TNT.

The Treaty of San Francisco, also called the Treaty of Peace with Japan, re-established peaceful relations between Japan and the Allies on behalf of the United Nations by ending the legal state of war, military occupation and providing for redress for hostile actions up to and including World War II. It was signed by 49 nations on September 8, 1951, in San Francisco, United States, at the War Memorial Opera House. Italy and China were not invited, the latter due to disagreements on whether the Republic of China or the People's Republic of China represented the Chinese people. Korea was also not invited due to a similar disagreement on whether South Korea or North Korea represented the Korean people.

The Korean Armistice Agreement is an armistice that brought about a cessation of hostilities of the Korean War. It was signed by United States Army Lieutenant General William Harrison Jr. and General Mark W. Clark representing the United Nations Command (UNC), North Korea leader Kim Il Sung and General Nam Il representing the Korean People's Army (KPA), and Peng Dehuai representing the Chinese People's Volunteer Army (PVA). The armistice was signed on 27 July 1953, and came into force at 22:00 local time (UTC+09:00) the same day and was designed to "ensure a complete cessation of hostilities and of all acts of armed force in Korea until a final peaceful settlement is achieved."

The Battles of Khalkhin Gol, known in Japan as the Nomonhan Incident after Nomonhan Burd Obo, were the decisive engagements of the undeclared Soviet–Japanese border conflicts which involved the Soviet Union, Mongolia, Japan, and Manchukuo in 1939. The conflict is named after the river Khalkhin Gol, which passes through the battlefield. The Soviet offensive, led by general Georgy Zhukov, utilized airplanes, tanks, and infantry in a simultaneous three-pronged offensive, the first of its kind in modern warfare. Similar tactics were later used during Operation Uranus at the Battle of Stalingrad.