Eastern Rumelia between the Balkan and Rhodope mountains gained semi-autonomous status with an Ottoman appointed Christian governor.

In response the Russians recalled all their officers which left the Bulgarian army virtually leaderless above the rank of captain.

In addition, the first line of the Eastern Rumelia militia had been mobilised consisting of 12 infantry battalions, 2 squadrons of cavalry, and 4 guns.

Confident of an easy victory and to some extent recognising that the war was not popular in Serbia, Milan only mobilised the active (first ban) army.

In response Alexander had to move his army from Eastern Rumelia to Sofia by all means available including the one limited railway line.

Alexander arrived on the evening of the 16th to find a well prepared defensive position manned by 9 battalions, plus some 2,000 volunteers and 32 guns, commanded by Major Guchev.

The position consisted of nearly 4 km of trenches and artillery redoubts either side of the main road on a ridge in front of Slivnitsa village.

The three Serbian centre divisions also arrived on the 16th and halted to recover after the fierce Bulgarian delaying action in the Dragoman Pass.

A relief column led by Captain Benderev recaptured the heights on the right and forced the Danube division back to the road.

However, three battalions of Bulgarian troops led by Captain Popov from Sofia had held the Morava division in the Visker Hills and the flanking move failed.

The main Bulgarian army crossed the border in two strong divisions (Guchev and Nikolaev) supported by flanking columns and converged on Pirot.

On 27 November the Bulgarian army flanked the right of the Serbian position with Prince Alexander personally leading the final attack.