Duke Dao of Qi (; died 485 BC) was from 488 to 485 BC ruler of the State of Qi, a major power during the Spring and Autumn period of ancient China. His personal name was Lü Yangsheng (呂陽生), ancestral name Jiang (姜), and Duke Dao was his posthumous title. Before ascending the throne he was known as Prince Yangsheng. Accession to the throne Prince Yangsheng was a middle son of Duke Jing of Qi. In the summer of 490 BC, the 58th year of Duke Jing's reign, the crown prince of Qi died. Although Duke Jing had at least five other grown sons, he made Prince Tu, his youngest son by his favourite concubine Yu Si, the new crown prince. Because Prince Tu was a young boy and his mother was of a lowly status, Duke Jing ordered the ministers Guo Xia of the Guo clan and Gao Zhang of the Gao clan to support Prince Tu and exile the other princes to the remote city of Lai. Duke Jing died soon afterward in the autumn of 490 BC. Guo and Gao installed Prince Tu on the throne, and the other princes escaped abroad. Yangsheng fled to the neighbouring State of Lu. However, the next year the Tian and Bao clans led by Tian Qi and Bao Mu staged a coup d'etat and defeated the Gao and Guo clans. Tian Qi brought back Yangsheng from Lu and installed him on the throne, to be known as Duke Dao of Qi. Bao Mu was reluctant to depose Prince Tu but dared not oppose Tian. Duke Dao soon killed Prince Tu, who is posthumously known as An Ruzi. The Tian clan would from then on increasingly dominate the power of Qi, eventually replacing the House of Jiang as monarchs of Qi in 386 BC. Battle with Lu When Duke Dao was exiled in the State of Lu, he married Ji Ji (季姬), younger sister of Ji Kangzi (季康子), who was the leader of the Ji clan, one of the three clans that controlled the power of Lu. After Duke Dao returned to Qi and ascended the throne, he sent for his wife in Lu. When Duke Dao was away, however, Ji Ji had an adulterous relationship with her uncle Ji Fanghou (季魴侯). Afraid that Duke Dao might discover his wife's infidelity, Lu refused to send Ji Ji to Qi. Enraged by