Via Militaris or Via Diagonalis was an ancient Roman road, starting from Singidunum (today the Serbian capital Belgrade), passing by Danube coast to Viminacium (mod. Požarevac), through Naissus (mod. Niš), Serdica (mod. Sofia), Philippopolis (mod. Plovdiv), Adrianopolis (mod. Edirne in Turkish Thrace), and reaching Constantinople (mod. Istanbul). This road was connected with Via Egnatia by other roads - the road along river Axios (or Vardar), the Serdica–Thessalonica road along river Strymon (or Struma), and the road Philippopolis–Philippi.