Problem: Background: Louis A. Szekely (born September 12, 1967), better known by his stage name Louis C.K. (), is an American stand-up comedian, writer, actor, and filmmaker. He is known for his use of observational, self-deprecating, dark, and shock humor. In 2012, C.K. won a Peabody Award and has received six Primetime Emmy Awards, as well as numerous awards for The Chris Rock Show, Louie, and his stand-up specials Live at the Beacon Theater (2011) and Oh My God (2013). He has won the Grammy Award for Best Comedy Album twice.
Context: In August 2005, C.K. starred in a half-hour HBO special as part of the stand-up series One Night Stand. Inspired by the work ethic of fellow comedian George Carlin, who had committed to dropping all of his existing material and starting over every year, In June 2006, C.K. starred in and wrote Lucky Louie, a sitcom he created. The series premiered on HBO and was videotaped in front of a studio audience; it was HBO's first series in that format. Lucky Louie is described as a bluntly realistic portrayal of family life. HBO canceled the series after its first season. He appeared in three films in 2008: Welcome Home Roscoe Jenkins, Diminished Capacity, and Role Models. C.K. launched his first hour-long special, Shameless, in 2007, which aired on HBO and was later released on DVD. In March 2008, he recorded a second hour-long special, Chewed Up, which premiered on Showtime Network on October 4, 2008, and was nominated for a Primetime Emmy Award for Outstanding Writing for a Comedy or Variety Special.  C.K. and his wife Alix Bailey divorced in 2008, with C.K. and Bailey sharing joint custody of their children. In a 2010 interview, C.K. talked about how, after his divorce, he thought, "well, there goes my act." He alluded to the way that his marriage had been central to his act and his life, and he said that it took him approximately a year to realize "I'm accumulating stories here that are worth telling." One element in his preparation for stand-up was training at the same boxing gym as Lowell, Massachusetts fighter Micky Ward, trying to "learn how to ... do the grunt work and the boring, constant training so that you'll be fit enough to take the beating."  On April 18, 2009, C.K. recorded a concert film titled Hilarious. Unlike his previous specials--which had all been produced for television networks--Hilarious was produced independently, directed by C.K. himself, and sold to Epix and Comedy Central after it was complete. As a result, it was not released until late 2010. It was published on DVD and CD in 2011. It is the first stand-up comedy film accepted into the Sundance Film Festival. From 2009 to 2012, C.K. played Dave Sanderson, a police officer and ex-boyfriend of Leslie Knope (played by Amy Poehler) in the sitcom Parks and Recreation. He also co-starred in the romantic comedy fantasy film The Invention of Lying, directed by and starring Ricky Gervais, in 2009.
Question: When did the sitcom air?
Answer: 

Problem: Background: Zheng He (Chinese: Zheng He ; 1371-1433 or 1435) was a Chinese mariner, explorer, diplomat, fleet admiral, and court eunuch during China's early Ming dynasty. He was originally born as Ma He in a Muslim family, later adopted the conferred surname Zheng from Emperor Yongle. Zheng commanded expeditionary voyages to Southeast Asia, South Asia, Western Asia, and East Africa from 1405 to 1433. His larger ships stretched 120 meters or more in length.
Context: In the decades after the last voyage, Imperial officials minimized the importance of Zheng He and his expeditions throughout the many regnal and dynastic histories they compiled. The information in the Yongle and Xuande Emperors' official annals was incomplete and even erroneous; other official publications omitted them completely. Although some have seen this as a conspiracy seeking to eliminate memories of the voyages, it is likely that the records were dispersed throughout several departments and the expeditions - unauthorized by (and in fact, counter to) the injunctions of the dynastic founder - presented a kind of embarrassment to the dynasty.  State-sponsored Ming naval efforts declined dramatically after Zheng's voyages. Starting in the early 15th century, China experienced increasing pressure from the surviving Yuan Mongols from the north. The relocation of the capital north to Beijing exacerbated this threat dramatically. At considerable expense, China launched annual military expeditions from Beijing to weaken the Mongolians. The expenditures necessary for these land campaigns directly competed with the funds necessary to continue naval expeditions. Further, in 1449, Mongolian cavalry ambushed a land expedition personally led by the Zhengtong Emperor at Tumu Fortress, less than a day's march from the walls of the capital. The Mongolians wiped out the Chinese army and captured the emperor. This battle had two salient effects. First, it demonstrated the clear threat posed by the northern nomads. Second, the Mongols caused a political crisis in China when they released the emperor after his half-brother had already ascended and declared the new Jingtai era. Not until 1457 and the restoration of the former emperor did political stability return. Upon his return to power, China abandoned the strategy of annual land expeditions and instead embarked upon a massive and expensive expansion of the Great Wall of China. In this environment, funding for naval expeditions simply did not happen.  However, missions from Southeast Asia continued to arrive for decades. Depending on local conditions, they could reach such frequency that the court found it necessary to restrict them: the History of Ming records imperial edicts forbidding Java, Champa, and Siam from sending their envoys more often than once every three years.
Question: why were they fighting the mongolians
Answer:
Starting in the early 15th century, China experienced increasing pressure from the surviving Yuan Mongols from the north.