Due to the Franco-Polish alliance, the formation of a Polish division in France began in early September 1939, shortly after the Invasion of Poland.

Altogether, the formation numbered eventually about 13,000 enlisted soldiers, 2,600 NCOs and 580 officers of all grades, when it was sworn in by Gen. Sikorski on 25 May 1940, shortly before arriving at the front in Lorraine.

At the end of April 1940, the division was moved to Colombey-les-Belles in Lorraine where it received its long-awaited heavy equipment and final training.

Fearing his corps being cut in two, the formation commander ordered the Poles to withdraw to the second line of defences.

As a result of the two-day-long Battle of Lagarde, the division was heavily damaged but managed to hold its positions.

[4][5] The 20th Army Corps' remnants, then composed mostly of the Polish division and a small detachment of the Fortified Sector of the Sarre, withdrew to the forests around Baccarat.