The Second Imperial Age, ruled by House Xy.ō, was the shortest dynasty in Xi'an history, lasting over 1700 Modern Xi'an Years (MXY). During this time, Xi'an explorers discovered multiple planetary systems and expanded the borders of the Xi'an Empire (SaoXy'an).
In MXY II.914 (SEY 291), they achieved first contact with the Kr'thak culture and attempted to establish a trade relationship. After several decades of strained relations, the Spirit Wars erupted, ravaging the latter half of the Age.
The entirety of House Xy.ō was killed in a bombing incursion by the Kr'thak in II.1706 (SEY 1305). This began the Dark, an era in which the Xi'an Empire had no official Imperial House. Xi'an historians group the Dark in with the Second Imperial Age, formally ending it at the ascension of House Kr.ē to the imperial throne in II.1824 (SEY 1457).