오초칠국의 난
By 196 BC, the Han court had replaced all but one of these kings (the exception being in Changsha) with royal Liu family members, since the loyalty of non-relatives to the throne was questioned. After several insurrections by Han kings—the largest being the Rebellion of the Seven States in 154 BC—the imperial court enacted a series of reforms beginning in 145 BC limiting the size and power of these kingdoms and dividing their former territories into new centrally controlled commanderies. Kings were no longer able to appoint their own staff; this duty was assumed by the imperial court. Kings became nominal heads of their fiefs and collected a portion of tax revenues as their personal incomes. The kingdoms were never entirely abolished and existed throughout the remainder of Western and Eastern Han.