Yen is 火 huo fire doubled to convey an idea of intensity. There is no term by which this word can really be translated in this connection. The meaning is that the Sung dynasty ruled under the guiding influence of fire as its own especial element. Hence Zottoli's rendering, "Ignea Sung," gives no clue whatever to the real signification, while Eitel's "glorious Sung" is altogether wrong.