Panhypersebastos

The title of grc () was a Byzantine court title created by Alexios I Komnenos () using the imperial root grc (the Greek translation of Augustus). It was always conferred to members of aristocratic families closely allied to the imperial family.

Michael Taronites, Alexios I's brother-in-law, was first awarded this title and regarded as almost equal to a Caesar. Under the Komnenian emperors, grc was one of the titles accorded to the emperor's sons-in-law (grc): the husband of the eldest daughter received the title of Caesar, the husband of the second daughter became grc, and those of the third and fourth received the titles of grc and grc respectively.

The title remained very important through to the Palaiologan era, coming right after the Caesar, but under Andronikos III Palaiologos (), when the future emperor John VI Kantakouzenos was named grc, the latter office was raised above the grc.

According to Pseudo-Kodinos, writing after the middle of the 14th century, the grc was distinguished by the yellow colour of his clothing: his shoes, his mantle (grc), as well as his saddle, were all yellow, decorated with gold braid. Otherwise his costume resembled that of the grc, i.e., a grc hat in red and gold, decorated with embroideries in the grc style, with a veil and pendants in the same style. Alternatively, a domed grc hat could be worn, again in red and gold, with a portrait of the emperor, standing crowned and flanked by angels, within a circle of pearls, in front. The grc itself was also bordered with pearls. A rich silk tunic, the grc, of two colours, decorated with stripes of gold braid, was also worn, and the staff of office (grc) featured carved knobs, with the first of plain gold, the second of gold bordered with silver braid, the third like the first, the fourth like the second, etc.