An Etymological Dictionary of the German Language/Vogt
Vogt, m., ‘overseer, steward, bailiff,’ from MidHG. vogt, voget, OHG. fógat (*fogā́t), m.; from MidLat. vocâtus, with the pronunciation of the Lat. v like f, as in Vers, Vesper (comp. Käfig). The MidLat. term is for advocatus (whence OHG. pfogát); comp. Fr. avoué, ‘defender of a church or abbey, attorney.’ MidLat. advocatus signified lit. ‘legal assistant,’ whence the meanings ‘guardian’ (MidHG. and ModHG. dial.) and ‘patron, protector.’ MidHG. voget denotes also ‘the protector of the Romish Church, King or Emperor of Rome, king and ruler (generally),’ and further ‘governor, legal official.’