The Tarnopol Castle originated as the residence of Jan Amor Tarnowski in 1540. Construction works (1540-1548) on the marshy bank of the Seret River

Seret River

The Seret is a minor river in Ukraine, a tributary of the Tysmenytsia River. The Seret flows through the center of Drohobych, a city located in Lviv Oblast in the west of Ukraine....

 were authorized by King Sigismund the Old. The castle (round which the modern town has developed) was encircled by a wooden fence and a deep moat

Moat

A moat is a deep, broad ditch, either dry or filled with water, that surrounds a castle, other building or town, historically to provide it with a preliminary line of defence. In some places moats evolved into more extensive water defences, including natural or artificial lakes, dams and sluices...

. The latter was connected in 1548 to the castle pond (see Ternopil Pond).

In the early 17th century, Ternopil passed through inheritance in the female line to Tomasz Zamoyski

Tomasz Zamoyski

Tomasz Zamoyski was a Polish-Lithuanian nobleman and magnate.Tomasz was the 2nd Ordynat of the Zamość estates. He was voivode of Podole Voivodeship in 1618, voivode of Kijów Voivodeship in 1619, starost of Kraków in 1628, Deputy Chancellor of the Crown in 1635, as well as starost of Knyszyn,...

 who commissioned extensive renovations. It was besieged by the Turks

Ottoman Empire

The Ottoman EmpireIt was usually referred to as the "Ottoman Empire", the "Turkish Empire", the "Ottoman Caliphate" or more commonly "Turkey" by its contemporaries...

 in 1544, 1575, 1589 and 1672. The Ottoman army under Şişman İbrahim Paşa reduced the castle to ruins in 1675. Count Korytowski revived it in the 1840s as his summer residence; he also had its towers, walls and other fortifications dismantled.