The birth of lantern, the appearance of hurricane lamp in Han Dynasty and introduction of Buddhism created a good condition for outdoor lamp and lantern show.
For the purpose of shielding wind, moving lamps and working at night, human being produced various kinds of practical lamp and lamp utensil via various vessels and fuels. Since thousands of years, human pursuit to the craftwork of lampshade has formed rich, colorful and fantastic lamp or lantern arts and laid a foundation for the lantern show.
At the earlier period of Western Han, Emperor Hanwendi stated the Jan. 15th of lunar calendar as the Lantern Festival, when he subjugated successfully the insurgency of Zhulu. Since the first Lantern Festival in Hanwudi (156B.C—87B.C.), every year at this time, emperor would offer sacrifice to the Heaven, Buddhist would light lamps to elucidate Buddhism, Taoist would sacrifice the deities Taiyi and Sanguan, common people would hold lamps and candles to chase rat, look at the silkworms and pray for big harvest and no disaster. Therefore, lamp, candle and fire gradually became scenery on the day of Lantern Festival.
The emergence of lamps and windproof lanterns in Han Dynasty facilitated the outdoor emplacement of lamps and lanterns. In ancient times, the 15th of the first lunar month was called Shang Yuan (first full moon); July 15th of the lunar month Zhong Yuan (mid full moon); October 15th Xia Yuan (last full moon). Shang Yuan was the first night with full moon in a year, so it was also named as Yuan Xiao Festival (full moon night). From the Warring States Period on, people prayed the God of Tai Yi from dush to dawn. Because of the eastward movement of Buddhism, on the night of Jan 15th in the first lunar month, bans on fire were lifted and lamps and lanterns were put outdoors all night long to symbolize the brightness of Buddhism. This was the precursor of the Lantern Festival.
In that night, the Emperors made a sacrifice to Heaven; Buddhists lit a fire to illuminate Buddhadharma; Taoists also prayed to Tai Yi and the gods in San Guan( Three Palaces); Folks also lit the candles and lamps to chase away the mice and light the silkworm in the hope of eliminating scourges and gaining a good harvest. Thus lamps, candles and fire became the essence of Shang Yuan. The Lantern Festival had its embryonic form when the wheels of time moved to the Northern and Southern Dynasties. Later it evolved into a majestic festival after Emperor Sui Yang Di took the throne.
So we can say Han Dynasty is one of the most important Dynasty for the Formation of the Lantern Festival.