Question: What was the former name of the birthplace of Yang Yu?

full_context: Document 1: Zhuang Yong: Zhuang Yong (; born August 10, 1972 in Shanghai) is a retired freestyle swimmer from China, whose best performance was winning the gold medal in the 100 m freestyle at the 1992 Summer Olympics in Barcelona, Spain. It was China's first gold medal in swimming. Four years earlier in Seoul she won China's first ever Olympic medal in swimming, ending up second in the final of the Women's 100 m Freestyle, behind East Germany's Kristin Otto.
Document 2: Zhejiang: Valleys and plains are found along the coastline and rivers. The north of the province lies just south of the Yangtze Delta, and consists of plains around the cities of Hangzhou, Jiaxing, and Huzhou, where the Grand Canal of China enters from the northern border to end at Hangzhou. Another relatively flat area is found along the Qu River around the cities of Quzhou and Jinhua. Major rivers include the Qiangtang and Ou Rivers. Most rivers carve out valleys in the highlands, with plenty of rapids and other features associated with such topography. Well-known lakes include the West Lake of Hangzhou and the South Lake of Jiaxing.
Document 3: Chen Hua: Chen Hua (born January 22, 1982 in Hangzhou, Zhejiang, China) is a two-time Olympic swimmer, and former World Record holder, from China. She swam for China at the 2000 and 2004 Olympics.
Document 4: Zhejiang: Zhejiang, as the heartland of the Jiangnan (Yangtze River Delta), remained the wealthiest area during the Six Dynasties (220 or 222–589), Sui, and Tang. After being incorporated into the Sui dynasty, its economic richness was used for the Sui dynasty's ambitions to expand north and south, particularly into Korea and Vietnam. The plan led the Sui dynasty to restore and expand the network which became the Grand Canal of China. The Canal regularly transported grains and resources from Zhejiang, through its metropolitan center Hangzhou (and its hinterland along both the Zhe River and the shores of Hangzhou Bay), and from Suzhou, and thence to the North China Plain. The débâcle of the Korean war led to Sui's overthrow by the Tang, who then presided over a centuries-long golden age for the country. Zhejiang was an important economic center of the empire's Jiangnan East Circuit and was considered particularly prosperous. Throughout the Tang dynasty, The Grand Canal had remained effective, transporting grains and material resources to North China plain and metropolitan centers of the empire. As the Tang Dynasty disintegrated, Zhejiang constituted most of the territory of the regional kingdom of Wuyue.
Document 5: Yellow Yeiyah: Yellow Yeiyah, last names also seen as two words "Yei Yah", (born 9 September 1984 in Ondo, Nigeria) is an Olympic swimmer from Nigeria. He swam for Nigeria at the 2008 Olympics.
Document 6: Yang Yu (swimmer): Yang Yu (; born February 6, 1985 in Hangzhou, Zhejiang) is a female Olympic medal-winning swimmer from the People's Republic of China. She became part of the Chinese national swimming team in 1999, and competed for Team China at the 2008 Summer Olympics.
Document 7: Gao Chang: Gao Chang (born January 29, 1987 in Jinan, Shandong, China) is a female Chinese swimmer, who competed at the 2004 Summer Olympics and who was a part of China's 2008 Olympic Team. She was part of the Chinese 4 x 100 m medley relay team at the 2012 Summer Olympics. Gao Chang won the gold in the 50-metre backstroke final of 2010 Asian Games.
Document 8: Elaine Chan (swimmer): Elaine Chan Yu Ning (; born March 15, 1988) is a two-time Olympic swimmer from Hong Kong, specialized in freestyle events. At age sixteen, Chan first competed at the 2004 Summer Olympics in Athens, where she finished forty-seventh in the women's 50 m freestyle, with a time of 27.48 seconds. Following her remarkable performance at the Olympics, Chan granted a full scholarship to the Ohio State University in Columbus, Ohio, where she trained with the college swimming team for 18 months. In 2007, Chan returned to Hong Kong to pursue her education with a bachelor's degree in economics and finance at the University of Hong Kong, while she trained with the national team in preparation for the Olympics. She qualified for the 2008 Summer Olympics in Beijing, and competed for the second time in women's 50 m freestyle. She swam in the seventh heat of the competition, with a time of 26.54 seconds, bettering her personal best from the previous Olympics, but finishing only in forty-fourth place.
Document 9: Nanjing: Being one of the four ancient capitals of China, Nanjing has always been a cultural centre attracting intellectuals from all over the country. In the Tang and Song dynasties, Nanjing was a place where poets gathered and composed poems reminiscent of its luxurious past; during the Ming and Qing dynasties, the city was the official imperial examination centre (Jiangnan Examination Hall) for the Jiangnan region, again acting as a hub where different thoughts and opinions converged and thrived.
Document 10: Li Xuanxu: Li Xuanxu (; born February 5, 1994 in Zhuzhou, Hunan) is a female Chinese swimmer, who competed for Team China at the 2008 Summer Olympics. At the 2012 Summer Olympics she qualified in second place in the heats with a time of 4:34.28 in the Women's 400 metre individual medley. She won the Bronze medal in the final with 4:32.91.
Document 11: Zhejiang: Despite the continuing prominence of Nanjing (then known as Jiankang), the settlement of Qiantang, the former name of Hangzhou, remained one of the three major metropolitan centers in the south to provide major tax revenue to the imperial centers in the north China. The other two centers in the south were Jiankang and Chengdu. In 589, Qiangtang was raised in status and renamed Hangzhou.
Document 12: Nanjing: Nanjing, one of the nation's most important cities for over a thousand years, is recognized as one of the Four Great Ancient Capitals of China, and had been the world's largest city aggregately for hundreds of years, enjoyed peace and prosperity and beared wars and disasters. Nanjing served as the capital of Eastern Wu, one of the three major states in the Three Kingdoms period (211-280); the Eastern Jin and each of the Southern Dynasties (Liu Song, Southern Qi, Liang and Chen), which successively ruled southern China from 317-589; the Southern Tang, one of the Ten Kingdoms (937-76); the Ming dynasty when, for the first time, all of China was ruled from the city (1368-1421); and the Republic of China (1927–37, 1945–49) prior to its flight to Taiwan during the Chinese Civil War. The city also served as the seat of the rebel Taiping Heavenly Kingdom (1851–64) and the Japanese puppet regime of Wang Jingwei (1940–45) during the Second Sino-Japanese War, and suffered appalling atrocities in both conflicts, including the Nanjing Massacre. It has been serving as the capital city of Jiangsu province after the China was established, and is still the nominal capital of Republic of China that accommodates many of its important heritage sites, including the Presidential Palace and Sun Yat-sen Mausoleum. Nanjing is famous for human historical landscapes, mountains and waters such as Fuzimiao, Ming Palace, Chaotian Palace, Porcelain Tower, Drum Tower, Stone City, City Wall, Qinhuai River, Xuanwu Lake and Purple Mountain. Key cultural facilities include Nanjing Library, Nanjing Museum and Art Museum.
Document 13: Nanjing: Since the Three Kingdoms period, Nanjing has been an industrial centre for textiles and minting owing to its strategic geographical location and convenient transportation. During the Ming dynasty, Nanjing's industry was further expanded, and the city became one of the most prosperous cities in China and the world. It led in textiles, minting, printing, shipbuilding and many other industries, and was the busiest business center in East Asia. Textiles boomed particularly in Qing dynasty, the industry created around 200 thousand jobs and there were about 50 thousand satin machines in the city in 18th and 19th century.
Document 14: Nanjing: During the period of North–South division, Nanjing remained the capital of the Southern dynasties for more than two and a half centuries. During this time, Nanjing was the international hub of East Asia. Based on historical documents, the city had 280,000 registered households. Assuming an average Nanjing household had about 5.1 people at that time, the city had more than 1.4 million residents.
Document 15: Nanjing: The city of Nanjing was razed after the Sui dynasty took over it. It renamed Shengzhou (昇州) in Tang dynasty and resuscitated during the late Tang. It was chosen as the capital and called Jinling (金陵) during the Southern Tang (937–976), a state that succeeded Wu state. It renamed Jiangning (江寧) in Northern Song dynasty and renamed Jiankang in Southern Song dynasty. Jiankang's textile industry burgeoned and thrived during the Song dynasty despite the constant threat of foreign invasions from the north by the Jurchen-led Jin dynasty. The court of Da Chu, a short-lived puppet state established by the Jurchens, and the court of Song were once in the city. Song was eventually exterminated by the Mongol empire under the name Yuan and in Yuan dynasty the city's status as a hub of the textile industry was further consolidated.
ground_truth: Qiantang
sub_queries: Yang Yu >> place of birth Answer: Hangzhou
What was the former name of Hangzhou ? Answer: Qiantang