Prior to the start of World War II, the 4th Infantry Division was initially commanded by Colonel Tadeusz Lubicz-Niezabitowski, and its peacetime headquarters was located in Toruń, with additional units stationed in Włocławek and Brodnica.
The 4th Division was originally part of the Pomorze Army and stationed northeast of Toruń, near the border of East Prussia.
In the area of Pokucie, its elements made contact with Romanian Army, which was allied with Poland, and which aided the Poles in the war against West Ukrainian People's Republic.
In early June 1919, after protests of Western Allies, the Blue Army was withdrawn from Eastern Galicia, together with Operational Group of General Daniel Konarzewski.
On June 24 the Ukrainians broke through the positions of the 3rd Division, and Polish forces had to withdraw to the line of the Swirz river.
In the second half of July 1919, 4th Infantry Division was loaded on trains and transferred to Brody, where it became part of Volhynian Front under General Antoni Listowski.
Local clashes took place along the front until late April 1920, when Polish General Staff ordered the destruction of Soviet 12th and 14th Armies, located in Volhynia and Podolia.
There, the division was reorganized and divided into three groups, commanded by Władysław Anders, Wladyslaw Tarwid and Stanislaw Tessar.
Following the Battle of Dęblin and Minsk Mazowiecki, the division was transferred to the 5th Army under General Władysław Sikorski, and on August 17 entered Zakroczym.
In early September 1920, 4th Infantry Division was transported back to Eastern Galicia, to the area of Lwów, as reserve force of the 6th Army.
The "new" 4th Infantry Division was transferred to Toruń, and before the Invasion of Poland it consisted of the following units: Following Plan West, 4th Division, commanded by Colonel Tadeusz Lubicz-Niezabitowski, belonged to Operational Group East (General Mikołaj Bołtuć), which was part of Pomorze Army (General Władysław Bortnowski).
Operational Group East was ordered to defend the approaches to Toruń, and shortly before the war, field fortifications had been built near Brodnica and Jabłonowo Pomorskie.
The task of the unit was to remain in battle readiness, in order to assault the enemy advancing from its positions behind the Osa river.
On September 3, 14th Infantry Regiment was attacked by the Luftwaffe, and as a result, Colonel Tadeusz Lubicz-Niezabitowski ordered a general retreat of the whole division.
On September 12 the division rested, while its staff decided to carry out a joint attack on Głowno, together with Wielkopolska Cavalry Brigade.
Due to stiff German resistance, Polish units had to withdraw to the northern bank of the Bzura river.
In a series of bloody skirmishes, it lost over 500 KIA, and was then ordered by General Boltuc to withdraw behind the Bzura, failing to seize the strategic town of Łowicz, with its railroad junction.
Their advance was temporarily halted, but other Wehrmacht units threatened the wings of the division, and Colonel Werobej decided to order a withdrawal.
In the morning of September 18 the 14th Regiment was ordered to protect the wings of Armies Poznań and Pomorze, which retreated towards Warsaw, via Kampinos Forest.
A skirmish took place along the road from Sochaczew to Wyszogród, after which the division suffered heavy losses and ceased to exist as a cohesive fighting unit.
As part of the First Army, this eastern incarnation of the 4th Division fought in Poland near Warsaw, at Kolberg, and north of Berlin in Germany during 1944–45.
By a Resolution of the Provisional Government of May 26, 1945, the division's personnel and equipment (with the exception of artillery and the sanitary battalion) served as a nucleus to form the staff and some branches of the Internal Security Corps (KBW).
Following reformation from two reserve infantry regiments, the division was stationed in the town of Krosno Odrzańskie as part of the Silesian Military District.