The task for the Entente forces on the Macedonian front was to inflict major defeats on the Bulgarian army and effect a breakthrough in the Balkans in a relatively short time.

The Allied command, which expected reinforcements, planned a major assault in the direction of Vardar and Doiran.

[3] The Allied command found that the Bulgarian positions were better fortified than the previous year, so it ordered a systematic artillery barrage on these defences.

To make the breakthrough, the British concentrated three divisions (the 22nd, 26th, 60th), with its artillery – more than 43,000 men, 160 guns, 110 mortars and 440 machine-guns.

The objective did not differ much from the battle in the previous year; the main blow was on a front of 5–6 km towards Kalatepe.

It included two prime positions with two rows of continuous trenches 1.5 – 2 metres deep, 200 to 1000 m apart and linked with passages for communication.

Twelve companies attacked the Bulgarian 2nd Brigade and, after a bloody fight, managed to take the "Nerezov," "Knyaz Boris," and "Pazardzhik" positions.

The main assault started at 9 pm with five waves of British troops attacking the Bulgarian positions.

[6] A Times correspondent wrote that the British soldiers called the "Boris" point "the valley of death.