("Republic of Korea" and "ROK" redirect here. For the Democratic People's Republic of Korea, see North Korea. For other uses, see Korea and ROK (disambiguation).) South Korea (), officially the Republic of Korea (ROK; ), is a sovereign state in East Asia, constituting the southern part of the Korean Peninsula. Highly urbanized at 92%, South Koreans lead a distinctive urban lifestyle; half of them live in high-rises concentrated in the Seoul Capital Area with 25 million residents and the world's sixth leading global city with the fourth largest economy and seventh most sustainable city in the world. The earliest Korean pottery dates to 8000 BC, with three kingdoms flourishing in the 1st century BC. The name Korea is derived from one of them, Goguryeo, also known as Koryŏ, which was a powerful empire and one of the great powers in East Asia, ruling Northeast China and parts of Russia and Inner Mongolia under Gwanggaeto the Great. Since their unification into Later Silla and Balhae in the 7th century, Korea enjoyed over a millennium of relative tranquility under long lasting dynasties with innovations like Hangul, the unique alphabet created by Sejong the Great in 1446, enabling anyone to easily learn to read and write. Its rich and vibrant culture left 17 UNESCO Intangible Cultural Heritages of Humanity, the third largest in the world, along with 12 World Heritage Sites. Korea was annexed by Imperial Japan in 1910 due to its strategic and central location, after whose surrender in 1945, it was divided into North and South Korea. A North Korean invasion led to the Korean War (1950–53). Peace has since mostly continued with the two agreeing to work peacefully for reunification and the South solidifying peace as a regional power with the world's 10th largest defence budget. South Korea's tiger economy soared at an annual average of 10% for over 30 years in a period called the Miracle on the Han River, rapidly transforming it into a high-income economy and the world's 11th largest economy by 1995. A long legacy of openness and focus in innovation made it successful. Today, it is the world's fifth largest exporter and seventh largest importer with the G20's largest budget surplus and highest credit rating of any country in East Asia. In 1987, it became a multi-party democracy with universal suffrage and is today Asia's most advanced democracy with high government transparency, universal healthcare, freedom of religion and fundamental rights protected by the most developed rule of law in East Asia. High civil liberties led to the rise of a globally influential pop culture such as K-pop and K-drama, a phenomenon called the Korean Wave, known for its distinctive fashionable and trendy style. Home of the UN Green Climate Fund and GGGI, South Korea is a leader in low carbon green growth, committed to helping developing countries as a major DAC and Paris Club contributor and rated highly in peaceful tolerance and inclusion of minorities. South Korea is East Asia's most developed country in the Human Development Index. It has the world's eighth highest median household income, the highest in Asia, and its singles in particular earn more than all G7 nations. Globally, it ranks highly in personal safety, education, job security, ease of doing business and healthcare quality, with the world's third highest health adjusted life expectancy and fourth most efficient healthcare system. It leads the OECD in graduates in science and engineering. Home of Samsung, the world's leading smartphone and TV maker, LG and Hyundai-Kia, South Korea was named the world's most innovative country in the Bloomberg Innovation Index, ranking first in business R&D intensity and patents filed per GDP. It has the world's fastest Internet speed and highest smartphone ownership, ranking first in ICT Development, e-Government and 4G LTE coverage. In 2005, it became the world's first country to fully transition to high-speed Internet and start the world's first mobile TV broadcast with 97% of cellphones already having Internet access.