In September 1919, General Smigly-Rydz's troops, forming part of the Lithuanian-Belarusian Front, came under Dyneburg and after the war fought the Soviets for the Daugava. These were the Latvian territories occupied by the Soviet 15th Army.
As a result, the sole advantage for Poland was the military alliance with Latvia.
It was not until December 30 that an agreement was reached and the date of the Polish-Latvian operation was set at the beginning of January.

Not for the first time nor the last in history - on both sides of the front stood soldiers of the same nation - same as the Poles - now they were Latvians.

The main forces will pass through the frozen Daughter towards the fortress, and a separate unit will force the river above the city and try to block the enemy's possible food in Wyszki.

The script depicts both parts of the action - both the September seizure of the left bank of the city - and the January acquisition of the center and fortress.
