《新五代史·本纪·唐本纪第五》
四月一日，晋王李存勖即帝位，大赦天下，改元同光，国号唐。
夏四月己巳，皇帝即位，大赦，改元，国号唐。
On April 1, the Prince of Jin, Li Cunxu, took the throne, granted a general amnesty to the world, and changed the reign name to Tongguang, with the national title Tang.