Megas doux

The megas doux (Greek: μέγας δούξ, pronounced [ˈmeɣaz ˈðuks], "grand duke") was one of the highest positions in the hierarchy of the later Byzantine Empire, denoting the commander-in-chief of the Byzantine navy. It is sometimes also given in English by the half-Latinizations megaduke or megadux. The Greek word δούξ is the Hellenized form of the Latin term dux, meaning leader or commander.

History and functions

The office was initially created by Alexios I Komnenos (r. 1081–1118), who reformed the derelict Byzantine navy and amalgamated the remnants of its various provincial squadrons into a unified force under the megas doux. The Emperor's brother-in-law John Doukas is usually considered to have been the first to hold the title, being raised to it in 1092, when he was tasked with suppressing the Turkish emir Tzachas. There is however a document dated to December 1085, where a monk Niketas signs as supervisor of the estates of an unnamed megas doux. The office of "doux [commander] of the fleet" (δούξ τοῦ στόλου, doux tou stolou), with similar responsibilities and hence perhaps a precursor of the office of megas doux, is also mentioned at the time, being given c. 1086 to Manuel Boutoumites and in 1090 to Constantine Dalassenos.

Initially, the office may have designated ad hoc commanders-in-chief placed in charge of combined naval and land expeditions, before coming to denote the head of the imperial fleet.

John Doukas, the first known megas doux, led campaigns on both land and sea and was responsible for the re-establishment of firm Byzantine control over the Aegean and the islands of Crete and Cyprus in the years 1092–93 and over western Anatolia in 1097. From this time the megas doux was also given overall control of the provinces of Hellas, the Peloponnese and Crete, which chiefly provided the manpower and resources for the fleet.