Question: When was the earliest known pottery created in the country which was the native land of Admiral Yi Sun-sin, who conducted the Battle of Happo? 

Passages:
The Lower Paleolithic era in the Korean Peninsula began roughly half a million years ago.  The earliest known Korean pottery dates to around 8000 BC, and the Neolithic period began after 6000 BC, followed by the Bronze Age by 800 BC, and the Iron Age around 400 BC. The statue of Admiral Yi Sun-sin is located at the Sejongno, Gwanghwamun Plaza in Seoul, South Korea.  It is dedicated to the 16th-century Korean war hero, admiral Yi Sun-sin.  It is considered one of Seoul's major landmarks and has been called "one of the most important instances of Korean public art". Battle of Jeokjinpo was fought on 8 May 1592.  After the Battle of Happo, further reports of an additional 13 Japanese ships prevented Yi Sun-sin and his fleet from resting long on the morning of May 8.  Admiral Yi once again ordered his fleet to pursue the Japanese in the direction of Jinhae.  The Korean forces caught up with the Japanese ships at Jeokjinpo, but the Japanese officers and crew abandoned their ships and fled into the mountains before the Koreans could fire upon them.  The Koreans easily sunk the 13 abandoned Japanese warships. The Battle of Happo was a naval engagement on May 7, 1592, one of the three Joseon naval campaigns of 1592 conducted by Korean admiral Yi Sun-sin during Japanese invasions of Korea (1592-1598) against the Japanese forces of Toyotomi Hideyoshi.  These campaigns made Yi a legendary figure in Korean History.  The campaigns of Yi were vital in halting the Japanese invasion. Immortal Admiral Yi Sun-sin (; lit.  "The Immortal Yi Sun-sin") is a South Korean television series based on the life of Yi Sun-sin, starring Kim Myung-min in the title role.  It aired on KBS1 from September 4, 2004 to August 28, 2005 on Saturdays and Sundays at 21:45 for 104 episodes. Won Gyun (Korean: 원균, hanja:元均 ; 12 February 1540 – 27 August 1597) was a Korean general and admiral during the Joseon Dynasty.  He is best known for his campaigns against Japanese during Hideyoshi's invasions of Korea.  Won was a member of Wonju Won family, which was well known for its members' military accomplishments.  He was born in 1540 near Pyeongtaek and demonstrated his skill as warrior at a young age.  He was qualified as a military officer and was first assigned to the northern border to defend against the Jurchens, who frequently raided Korean villages.  Won led many successful campaigns with Yi Il and Yi Sun-sin against the Jurchens.  After considerable accomplishments on the northern frontier, he was promoted to admiral in 1592 and sent to the southern coast of Gyeongsang Province to command the province's Western Fleet, along with Yi Sun-sin, who became admiral before Won and took command of Jeolla Province's Eastern Fleet.  At the time, Won and Yi were cavalry leaders who had no experience with naval warfare. Tongyeong (] ) is a coastal city in South Gyeongsang Province, South Korea.  In 2010, it had an area of 238.81 km and a population of 139,869 people.  It is divided into 1 eup (town), 6 myeon (township) and 11 dong (neighborhood).  Chungmu city and Tongyeong county were reunited in 1995, creating Tongyeong City as it is known today.  It consists of Goseong Peninsula, Hansan Island, Mireuk Island and other islets.  It was formerly known as Chungmu, after the posthumous name of Admiral Yi Sun-sin.  The name Tongyeong means "command post" and is itself associated with Admiral Yi, as it refers to his principal base that was located on nearby Hansan Island. Nanjung Ilgi or War Diary of Yi Sun-sin is the personal diary of Admiral Yi Sun-sin (Hangul: 이순신, Hanja: 李舜臣), a Korean naval commander who lived during the Joseon Dynasty.  It was written between January 1, 1592 and November 17, 1598, a first person narrative of the admiral's perspective on the Japanese invasions of Korea in the late 16th century. The naval Battle of Hansan Island, also known as the Battle of Hansando, took place on July 8, 1592, near the Korean island of Hansan.  Korean admiral Yi Sun-sin destroyed at least 47 Japanese ships, captured 12.  This battle is also the first in Admiral Yi's 3rd Naval Campaign.  The battle, one of the three great battles won by Joseon during the Imjin Waeran, carried great import, because Joseon's forces now came to dominate the southern seas.  After Hansan-do Toyotomi Hideyoshi ordered the Japanese navy to avoid direct engagement with the Joseon navy and instead station itself in fortifications along the coast to defend important sea lands. The Joseon naval campaigns of 1592 was naval campaigns conducted by Korean admiral Yi Sun-sin during Japanese invasions of Korea (1592-1598) against the Japanese forces of Toyotomi Hideyoshi.  These campaigns made Yi a legendary figure in Korean History on par, if not surpassing the great general Eulji Mundeok.  The campaigns of Yi were vital in halting the Japanese invasion, which had the ultimate aim of conquering not just Korea, but Ming China as well.  Yi was able to severely impair Japanese logistics and reinforcements for the land forces in Korea.

Supporting sentences:
 These campaigns made Yi a legendary figure in Korean History. The Lower Paleolithic era in the Korean Peninsula began roughly half a million years ago.  The earliest known Korean pottery dates to around 8000 BC, and the Neolithic period began after 6000 BC, followed by the Bronze Age by 800 BC, and the Iron Age around 400 BC.