From the 5th century BC until the 10th century,
Yotvingians, a
Baltic tribe close to the
Lithuanians, lived in the areas around Ciechanowiec. From the 13th–14th centuries until 1513, the lands belonged to the
Trakai Voivodeship of the
Grand Duchy of Lithuania. Then, they were part of the
Podlaskie Voivodeship from 1513 until 1795 (1513–1569 as part of Lithuania and 1569–1795 as part of the
Kingdom of Poland in the
Polish–Lithuanian Commonwealth). In 1429, the
Grand Duke of Lithuania Vytautas the Great granted Ciechanowiec the settlement
Magdeburg rights and its coat of arms. In the 16th century, the town belonged to the
Kiszka family. In the mid-16th century Castellan of
Trakai,
Piotr Kiszka built a castle on the right bank of the river
Nurzec, northeast of the town. Between 1617 and 1642, Mikołaj Kiszka ordered to build heavy defensive walls around the fortress, but soon the castle burned down during the
Deluge, and the surviving buildings with the newly built residence for the Ossoliński family were later blown up and destroyed by the
Imperial Russian Army during
World War I (1915). To this day only the foundations and the moat still exist. The forthcoming owners of the town were: The Bremmer, Ossoliński, Szczukow and Ciecierski families. In particular, the Ossoliński family in the second half of the seventeenth century invested in the development of the town. In 1736–1739, a brick church of the Holy Trinity and the Sisters of Mercy hospital was built, according to the draft of Warmia's architect Jan Adrian Kluk. His son, Fr.
Jan Krzysztof Kluk (1739–1796), the local parish priest, devoted to natural history, became one of the most important Polish naturalists of the Enlightenment. He is the author of the first comprehensive textbook in the
Polish language on agriculture, as well as other pioneering scientific topics, as well as school textbooks written on request of the
Commission of National Education. The scope of the research included both
botany and
zoology, and natural pharmaceuticals. In the era of the partitions, Ciechanowiec was passed onto Prussia, and after the
Congress of Vienna to the Russian Empire. Later the town was divided into two parts: right bank (called New Town or "Polish section"), was part of the Polish Kingdom and the left bank Old Town ("Rus section") in Russia. As a result of the
November and
January Uprisings, the right bank of Ciechanowiec lost the town rights in 1870. At the end of the nineteenth century, the textile industry rapidly developed in the town. Ciechanowiec was also very popular for various horse fairs. Significant damage from the times of
World War I and the
Polish–Soviet War were slowly repaired in the interwar period. Before the beginning of
World War II, 55% of the town's inhabitants were
Jews. At that time the town was known to a large number of workshops, mainly Jewish. In 1938, the left bank of Ciechanowiec (then located in the district of Bielsko) was attached to the right part of the town (on the status of the settlement), previously located in the district of Wysokomazowieckie (in the municipality of Klukowo). During
World War II, the town was badly destroyed, as a result of the
Molotov–Ribbentrop Pact, first by the soldiers of the Red Army, and after June 1941 by the
German Army. The Jewish population was almost completely exterminated at the
Treblinka extermination camp. After the war, reconstruction lasted a long time and the town has not regained its former importance and population that it once had. Jewish family names like
Ciechanowiec, Ciechanowiecki, Ciechanowicz, Ciechanowski and
Chechanover originated from this town. ==Geography==