Duke Ding of Lu

Duke Ding of Lu (Chinese: 魯定公; pinyin: Lǔ Dìng Gōng, 556 BC – 15 May 495 BC) was a ruler of the State of Lu during the Spring and Autumn period of ancient China. His ancestral name was Ji (姬), given name Song (宋), and Duke Ding was his posthumous title.

Since the reign of Duke Xuan of Lu, The politics of Lu had been dominated by multiple cadet branches of the ducal house, particularly the Three Huan: Jisun (季孫), Shusun (叔孫), and Mengsun (孟孫). Efforts of Confucius, who served as Duke Ding's Minister of Crime (大司寇), to curb the power of the Three Huan were met with failure. Eventual political differences and externally-fomented discord caused Confucius to go on exile, seeking to realize his ambitions elsewhere.