The Bulgarian 2nd Army commanded by General Nikola Ivanov held a line from Lake Dojran south east to Kilkis, Lachanas, Serres and then across the Pangaion Hills to the Aegean Sea.

The army had been in place since May and was considered a veteran group having fought at the siege of Adrianople in the First Balkan War.

On 16 June, the Bulgarian force included approximately 75,000 men and 175 guns in 57 infantry battalions, 10 cavalry squadrons and 37 batteries.

[1] General Ivanov claimed after the war that his Army consisted of only 36,000 men of whom 20,000 were "still untrained" and that many of his units were understrength.

Although General Ivanov probably underestimated the number of his soldiers, he still faced a much larger Greek enemy.

[4] The Greek army, commanded by King Constantine I, had 8 divisions and a cavalry brigade (117,861 men) with 176 artillery guns[5] in an 80 km line extended from the Gulf of Orphanos to the Gevgelija area.

The Greek plans were defensive in nature and they expected that the Bulgarians would strike first in a thrust to capture Thessaloniki.

[6] At Kilkis, the Bulgarians had constructed strong defenses including captured Ottoman guns which dominated the plain below.

On 20 June, despite having committed all forces and advancing steadily, the Greeks failed to break the Bulgarian defence.

The 10th division was ordered to disengage from the enemy at Kalinovo (renamed Soultogianneika between both world wars) and send forces southward to participate in the fighting of Kilkis while the 1st and 6th divisions (at the time engaged in the direction of Lachanas) was ordered to create a 6-battalion strong detachment plus mountain artillery to reinforce the forces attacking Kilkis on the flank.

Acting under the previous order of the Greek HQ which requested Kilkis be captured by the night of 20 June, the 2nd division went forward alone.

In the three days battle around Kilkis, the Greeks suffered heavy casualties totalling 5,652 killed and wounded.

On 19 June, the Greek 6th division advance from Assiros (Yuvesna) toward Lachanas and succeeded in capturing the Dichalo-Klepe line after losing some 530 men.

During the night of 20 June, the order from HQ to create a detachment to hold the forces attacking Kilkis arrived.

The Greeks captured Dojran on 5 July but were unable to cut off the Bulgarian retreat through Struma Pass.