G'Kar served as the Narn ambassador to Babylon 5 for about five years, starting when the station opened in 2258. While Narn was occupied by the Centauri, G'Kar remained on the station as a political refugee. He continued to represent Narn to the Interstellar Alliance after its foundation, refusing to accept an executive role in the post-war Narn government. He died in 2278, mutually strangling Londo Mollari.
Like all Narns, G'Kar appears to be somewhat stronger and substantially tougher than a human, but somewhat less agile. At some point before he was stationed on Babylon 5, G'Kar had "gills" surgically implanted in his neck that allow him to breathe normally in toxic atmospheres; the limits of these "gills" are undefined.