On 10 July, Austrian troops embarked on a march; after two days they reached
Gradiška. Heavy rains fell and there was some minor resistance from the local
Bosnian Muslim population, causing the Austrians difficulties in crossing the
Sava. Five days later, the crossing succeeded, and with no more significant resistance they headed towards
Banja Luka. The Austrian army reached
Kijevci, where Hildburghausen sent General von Muffling with 7
infantry battalions, of which 3 battalions consisted of Croatian allies, 400
horsemen and 4
cannons – to take a detour to protect the Austrian army from a surprise attack.
First skirmish On 20 July, the Austrian army advanced towards
Jurkovići. This is where the first significant battle with the Bosniak army, commanded by Sali Aga, took place. Sali Aga had three groups of 1,000, 2,000 and 5,000 soldiers at his disposal, which surprised the Austrians. Sali Aga fought Muffling man to man and they wounded each other. Sali Aga died immediately, while Muffling succumbed two days later. The battle was an Austrian victory.
Siege of Banja Luka Two formations of the Austrian army – one under the command of Field Marshal Goldy and the other under Hildburghausen – joined in front of Banja Luka on 27 July. One kilometer from the
Banja Luka fortress, the Austrian army raised a camp. Hildburghausen demanded that the city be surrendered unconditionally, which the defenders refused. The siege of the city began, and after three days the Austrians regrouped forces and on 27 July began firing with artillery at the fort. Between 27 July and 4 August, approximately 1,800 shells were fired daily. The defense of
Banja Luka was commanded by
Mehmed-beg Ćatić; in the early days, the defenders gave strong resistance to the Austrian army. The cannon gunners of the Austrian army did not aim precisely but when the cannons were moved forward, the city center was targeted, forcing the civilian population to retreat deep into the underground walls. Hildburghausen sends a letter to Captain Ćatić demanding that he surrenders: Ćatić's officers declared they would not surrender and Hildburghausen received an answer:
Hekimoğlu Ali Pasha arrives to help After the Austrians received news that Hekimoğlu Ali Pasha had set off with 15,000 troops to help the Banja Luka people, the city was even more heavily targeted. Ćatić sent a letter to the Travnik vizier, which was carried through enemy lines by disguised Bosniak soldiers. However, the letter did not reach the vizier because they had already met the army of Hekimoğlu Ali Pasha and it had been handed over to him. On 3 August, Hildburghausen's scouts informed him that unknown soldiers were spotted in the surrounding woods, but he made the fatal decision not to follow it further. This enabled the Bosniak army to approach the Austrian camp unnoticed. Hildburghausen expected (though he misjudged the timing) that help would be given to the Bosniak army, and he regrouped the soldiers. Generals Succoi and Rommer guarded the right flank while Major General Baranyay shifted the artillery to the left bank of
Vrbas. A considerable number of soldiers were left in reserve. While the Austrians regrouped, the defense troops did the same. The right wing of the army, which came to the aid of the defenders, was commanded by Captain
Mehmed Bey Fidahić; 4th
sanjak of the Bosnian eyalet is placed on the left wing. Among the soldiers were
ulema,
muderis, etc. There were also Orthodox people faithful to the Bosnian Eyalet and
Franciscans who provided material assistance to the army. Prior to the arrival of the relieve force, the ratio of attackers to defenders was about 3 to 1; the Austrian army had about 17,000 and the Bosniak had 5,000 men.
Main battle As soon as troops under the command of Hekimoğlu Ali Pasha attacked the Austrian army on the morning of 4 August, the defenders began to attack on the left bank of the Vrbas. Austrian troops, under the command of Baranyay, repelled the onslaught of the defenders. During the battle, the Austrian officers deviated from the plan set by Hildburghausen, thereby unknowingly assisting the defenders; a big mistake was made by Baranyay for not deploying his infantry. One part of the Austrian army was not following the original orders, so a disturbance was caused in their ranks, and it was not possible for the army to establish a single infantry line. Bosniak cavalry used this and attacked the Austrian army center, causing them great losses. When the defenders managed to occupy the pontoon bridge, the Austrian troops on the left bank of the Vrbas began to retreat. Mehmed Pasha, who noticed this, attacked fiercely the Austrian troops who were still resisting. Hildburghausen ordered his troops to reinforce the left bank of the Vrbas, thereby aiding Baranyay. This move by Hildburghausen was later regarded as a major mistake of his, as it turned out that Baranyay was strategically incapable and unable to use these reinforcements. The Austrian army on the left bank of the Vrbas was trying to escape by crossing the river, but many were non-swimmers and drowned in the river. Five soldiers each held the horses' tail to cross the river. The right wing offered even considerable resistance; the defenders carried out five attacks during the day. On the evening of 4 August, Hildburghausen ordered a withdrawal.
Chase after the Austrian army Mehmed Ali-Pasha orders on 5 August to pursue the fleeing Austrians. As the
Bosniak troops went partly unorganized in the pursuit, 500 soldiers were lost near
Klašnica when they reached the Austrian troops. On 13 August, Hildburghausen arrived in
Slavonska Gradiška, where he awaited the rest of the army until 20 August.
Consequences About 600 defenders were killed, while the Austrian army lost about 300 troops in the direct combat. An unknown number of Austrian soldiers—according to estimates 1,000 from Hildburghausen's camp alone—drowned in the Vrbas. At least 1,200 soldiers were wounded. The Bosniak army seized 12 cannons, 315
tents, thousands of
barrels, and many
rifles,
sabers and other military equipment. The Croatian Ban
Josip Esterházy, who left
Bužim after the defeat of the Austrian army, explained the defeat by the lack of heavy artillery. Austrian officers cited lack of discipline among soldiers as the main reason. ==Notes==