In 1807, it was regained by Poles and included within the short-lived Polish Duchy of Warsaw.

From 1886, Strelno experienced an economic boom as a district capital, and was connected to the Prussian State Railway in 1892.

Polish insurgents captured the town on January 2, 1919, and it became again part of Poland.

[5] During the German occupation of Poland during World War II, the Polish population was subjected to mass arrests, deportations, murder and expulsions.

Many Poles, including activists and teachers, were either murdered or deported to concentration camps during the Intelligenzaktion.

In 1939, the families of the victims, as well as owners of larger houses, shops, workshops and barbershops were expelled to the General Government, and their property was handed over to Germans as part of the Lebensraum policy.