Demetrius was a son of King Alexander I of Imereti (died 1389), who had broken away from the Kingdom of Georgia during Timur's invasions of that country in 1387.
His accession was prevented, however, by King George VII of Georgia, who, once freed from a protracted war with Timur, invaded Imereti.
The Dadiani of Mingrelia and Imeretian nobles captured Demetrius and delivered him to George, who treated him with consideration and sent him to a safe retreat in Somkhiti, in Kartli.
[1] A claim by the early-18th-century Georgian historian, Prince Vakhushti, that Bagrat VI, the forefather of the subsequent dynasty of Imeretian kings, was Demetrius's son is false.
It has been rejected by a number of scholars and Cyril Toumanoff eventually elucidated Bagrat's true origin as a grandson of Constantine I of Georgia.