Spring offensive of the White Army

The Spring Offensive of the Russian Army was an offensive of the White Army of the White movement led by Alexander Kolchak on the Eastern Front of the Russian Civil War, between March and April 1919.

Background

At the end of 1918, the situation on the Eastern Front of the Russian Civil War was unclear. Both sides fought for the Kama River. The Supreme Command of the Red Army prepared for major offensives on the Southern and Western fronts, hence there were no supplies available for the Eastern front. At the end of December, the Whites conquered Perm on the northern flank, but the Reds captured Ufa on the southern flank. On 22 January 1919 the Red 1st Army connected with the Army of the Turkestan Autonomous Soviet Socialist Republic, which had advanced from Middle Asia. On 24 January the Red 4th Army captured Uralsk.
At the beginning of 1919, the Supreme Command of the White Army decided to advance in two directions. The purpose of the northern advance was to connect with the North Russia Front and to strike at Petrograd; the purpose of the southern advance was to crush the Red front on the middle Volga river and to advance to Moscow.
The Whites had three armies:

Orenburg Independent Army on the southern flank, from May renamed the Southern Army of 25,000 men under General Petr Belov
Western Army in the middle between Birsk and Ufa
Siberian Army on the northern flank between Glazov and Perm
Another 25,000 Orenburg and Ural Cossack fighters, south of the Dutov-Belov Army.

The Reds had three armies in the south:

4th Army,
Turkestan Army and
1st Army in the region to the north of the Caspian Sea

and three armies to the north of them:

5th Army, defending a 200 km front in the center
2nd army, near Sarapul
3rd Army, near Perm railway.

Therefore, on the northern flank both sides were equal, the Whites were stronger in the center, and the Reds had an advantage on the southern flank. Both sides decided to strike on the right flank and to cut the communication lines of their opponent's left flank. At the end of February, the Whites pushed back the left flank of the Reds' 2nd Army, forcing it to retreat.

Offensive

On 4 March, the Siberian Army of the Whites began its advance. On 8 March it captured Okhansk and Osa and continued its advance to the Kama River. On 10 April they captured Sarapul and closed in on Glazov. On 15 April soldiers of Siberian Army's right flank made contact with detachments of the Northern Front in a sparsely populated area near the Pechora River.
On 6 March Hanzhin's Western Army stroke between the Red 5th and 2nd Armies. After four days of fighting the Red 5th Army was crushed, its remains retreated onto Simbirsk and Samara. The Reds had no forces to cover Chistopol with its bread storages. It was a strategical breakthrough, the commanders of Red's 5th Army fled from Ufa and the White Western Army captured Ufa without a fight on 16 March. On 6 April they took Sterlitamak, Belebey the next day and Bugulma on 10 April.
In the South, Dutov's Orenburg Cossacks conquered Orsk on 9 April and advanced towards Orenburg.
After receiving information about the defeat of the 5th Army, Mikhail Frunze, who had become commander of the Red Southern Army Group, decided not to advance, but to defend his positions and wait for reinforcements. As a result, the Red Army was able to stop the White advance on the southern flank and to prepare its counteroffensive.

Aftermath

The White Army had made a strategic breakthrough in the center, but the Red Army had been able to prepare its counteroffensive on the southern flank.
On April 22, Mikhail Frunze launched his successful Eastern Front counteroffensive against the over-extended Western Army.