Her European possessions formed two separate theatres of war, Macedonia and Thrace, which were linked only by the coastal railway Dede Aghach - Seres - Salonika, and this line, open in its middle section to Bulgarian raids from the mountains on the N.
Instead of 3 divisions, I only was to operate in Macedonia, and this was directed to move independently from Dupnitsa in the direction of Seres and Salonika.
frankly began its march over Jumaya Pass into the Struma valley, heading for Seres.
For their part the Bulgarians used the railway lines Adrianople - Sofia and Dede Aghach - Seres (the latter secured by the conquest of the coastal region by the 7th and 2nd Divs.
The Bulgarian scheme of operations, necessarily offensive, suffered from the weakness of having two objectives - the Ovche Polye and Salonika - and being based on two main lines of communication diverging towards the rear - Kyustendil and Seres - Drama.