Christopher was given the position of megas hetaireiarches (commander of the palace guard) in spring 919, after Romanos assumed the position of basileopator. Romanos, in order to give his family precedence over the more Macedonian line, raised Christopher to co-emperor on 21 May 921. In 928 Christopher's father-in-law, Niketas, unsuccessfully attempted to incite Christopher to usurp his father, resulting in Niketas being banished.