《资治通鉴·唐纪·唐纪十一》
己未，太宗下诏荆州都督、荆王李元景等二十一位亲王所任的刺史职务，均由其子孙世袭。
己未，诏荆州都督荆王元景等二十一王所任刺史，咸令子孙世袭。
On Jiwei, Emperor Taizong issued an edict to make the positions of governor that were held by twenty-one imperial princes, such as Li Yuanjing, governor of Jingzhou, hereditary for their descendants.