In summer 431, Emperor Taiwu made his first proposal of a marriage between the two imperial families to Liu Song. (Based on subsequent events, it appeared to be a proposal of marriage between a son of his and a daughter of Emperor Wen's, but by this point it was not completely clear.) Emperor Wen responded to it ambiguously. From this point on, Emperor Taiwu would repropose the marriage on a nearly yearly basis, with the same kind of response from Emperor Wen. At the same time, however, he did enter into peaceful relations with Rouran, by returning a number of captured Rouran generals.