The oldest mention of the Mossakowski family comes from 1597. The family comes from the family nest, which is the village of Moszaki (Mosaki or Mossaki) in the Ciechanów County. Initially, the village was called Grudowo, which is first mentioned in 1426. The Mossakowski family begins with Stanisław Moszak and his father Mosz. The area of land they owned was about 500 hectares and the family received them from the granting before 1414.
Michał Mossakowski had three sons: Aleksander, Józef and Roman, and two daughters: Anna and Marianna.
It is known that the son Roman was a priest ordained on June 17, 1883. His second son Józef Mossakowski was the heir in Zawidz Mały near Sierpc. He sold it around 1914 and with the money obtained from the sale, he bought a large house in Płock with rooms for rent.
The reason for the sale was Józef's poor health. He was afraid that his wife, Zofia, would not be able to manage the property, and that the money earned from renting rooms would allow the family to support themselves. Józef and Zofia Massakowski had six children: Zymunt, Edward, Halina, Wacława, Ferdinand and Konrad, who died as a child.
Zygmunt Wojciech Mossakowski (23 May, 1899-1940). He was a constable in the State Police in Płońsk in September 1939. He was arrested by the Russian NKVD, deported to Ostashkov and shot. Zygmunt is buried in Miednoje. He was married to Maria Kupść and had two daughters, Irena (1932 -) and Katarzyna (1938-2005).
Edward Mossakowski (1903-1939). He died in September 1939 and orphaned two sons, Andrzej and Zbigniew. Andrzej was an electrician. Zbigniew graduated in wood processing. He was the director of a furniture factory in Inowrocław.
Halna Mossakowska Kawecka (1901 - 2002) She married Lucjan Kawecki. They had two daughters, Jadwiga and Alina. The marriage did not last long and Halina moved to Sierpc with her mother, Zofia.
Ferdynand Mosakowski (1908-1971) changed the spelling of the surname from Mossakowski to Mosakowski. Supposedly, a surname with a double "s" indicated a noble origin, and it was especially unwelcome in People's Poland in the years 1947 - 1956. Ferdinand left Płock for Biłgoraj. He married Łucja Budzyńska, with whom he had five children: Zofia, Krystyna, Hanka, Janusz and Jacek.
Wacława (1906 - 1995) graduated from the Pedagogical Secondary School in Płock, after getting married to Paweł Wyczałkowski. After the wedding, she moved to Katowice, where Janusz, Teresa and Wojtek were born. After the war, she and her family moved to Wrocław.