After the death of Roman Komierowski, the estate was inherited by his son, Tomasz, who between 1924 and 1929 expanded the palace in a neo-Baroque and neoclassical style, according to the design by architect Adam Ciborowski. The last owner of Komierów, Tomasz, was shot by the Germans in September 1939, and the German army made the palace their headquarters, remaining there until the end of the war.
The German occupation, followed by the Soviet occupation, spared neither the palace collections, the library, nor the family portrait collection, carefully gathered since the 15th century.
In the post-war years, the palace served various functions: a work center for prisoners, a warehouse, the headquarters of the State Agricultural Farm (PGR), and a youth riding camp center. The son of the last owner of the estate, Andrzej, lived outside Poland after the war.
He returned to his homeland in 1991 because a law was to take effect regarding the return of properties to their rightful owners. Unfortunately, this law never became a reality, and Andrzej (5th from the left), along with his wife Janina Komierowska (1st from the left), spent the last years of their lives in Sępólno Krajeńskie. He died in 1994 in Bydgoszcz. According to his wish, he was buried in the Komierowo cemetery.
In 2003, the palace was purchased from the State Treasury by a Mazovian family line. The building was ruined, and other elements such as the roof and gutters were continuously stolen and vandalized by local thieves. The family tried for many years to obtain financial
support from the State for the palace's reconstruction, but they never received it.
The renovation of the palace was entirely funded by the Komierowski family from their own resources, without any help from the State.
