Tellas Vornai or field hieracchies were nonstandard chains of command that the Romulan Star Navy employed during wartime. Tellas Vornai saw the Tal Diann's belisaro take command of the unified Star Navy. This was done due to the political nature of the Star Navy in the 24th century. These special chains of command made it so that the political balance set during peacetime would not be greatly upset in times of war. (The Dominion War Sourcebook: The Fires of Armageddon)