It is unclear when the beginning of the year was celebrated before the Qin Dynasty. Traditionally, the year was said to have begun with month 1 during the Xia Dynasty, month 12 during the Shang Dynasty, and month 11 during the Zhou Dynasty. The first Emperor of China Qin Shi Huang changed the beginning of the year to month 10 in 221 BC, also changing the location of the intercalary month to after month 9. Whether the New Year was celebrated at the beginning of month 10, of month 1, or both is unknown. In 104 BC, Emperor Wu of the Han Dynasty established month 1 as the beginning of the year, where it remains.