[1] Vytautas copied the Polish system of administrative division in order to centralize and strengthen the government.

The Duke of Trakai (Latin: dux Trocensis) was replaced by appointed officials – voivodes and his deputy castellan.

The voivodeship was divided into four powets [be]: Grodno, Kaunas, Trakai (ruled directly by the voivode), and Upytė.

The Voivode of Trakai (Polish: Wojewoda trocki, Lithuanian: Trakų vaivada) was one of the most important state offices in the Grand Duchy of Lithuania.

They were appointed from prominent magnate families and competed only with voivode of Vilnius and Grand Chancellors for power and prestige.