Onuškis was first mentioned in written sources in 1499. Grand Duke of Lithuania Aleksandras issued a privilege, according to which he gave Jurgis Astikas the grove together with the manor, built by Hanusas Gailiminaitis without permission. Although Hanusas was kicked out of the estate, his built estate was further called Hanušiškiai.
In 1609, the last representative of the Astikai in Onuškis died and the manor was passed to the Duninai-Rajeckiai family. In the 18th century, noblemen Chominskiai purchased the manor. In the inventory of 1791, it was indicated that a dwelling house of Chominskiai estate was built of hewn logs covered with straw. The front room led to the inside of the house, and behind it were several rooms, in which there were rookeries, a stove, and a bakery along the walls. The house was very modest, so it is believed that the owners did not live in it. In the yard there were barns, stables, hayloft, the garden was fenced with sharp stakes with a gate.
At the turn of the 18-19th centuries, the estate belonged to Komarai. In 1830-1840, Teofilis Komaras constructed a late classical style manor house believed to have been designed by architect Cesaris Laurynas Anikinis. The manor was on a hill, on either side of the road leading to Courland. It was a rectangular building with a two-story central section and one-story side wings. The facade of the manor house, the center of which stood out against a background of 11 columns, faced the park, while a portico with four columns, above which a triangular pediment loomed, marked the facade facing the road. The drawing by Napoleon Orda, made in the 1870s, shows square pavilions along the sides of the estate, but by the 20th century, they were gone. There is almost no information about the interior of the manor. The manor is believed to have had a large hall, which was called a billiard room, from which two corridors led to small rooms.
The entrance gate was set in front of the main axis of the manor, and the entrance was paved with stone pavers. Colored flowerbeds separated the manor from the road, and on the other side was a barn with columns of the same style. The outbuildings on the sides of the flowerbeds and the servants' buildings, together with the manor house, formed a representative, semi-enclosed courtyard.
In the 19th century, an English-style park appeared. Spruces, lindens, maples, larches, lilacs, and rarer species of trees grew here. All the trees were planted in groups so that there was a view through the windows on the front side. A pond was dug at the bottom of the park into which water from the surrounding springs flowed.
During World War I, the manor burned down, and in 1919, Vitoldas Komaras, the last male member of the family, died. During independence, the estate was called Onuškis in Lithuania, but its grandeur faded – the manor was not rebuilt, Vitoldas' wife Marija and her daughter lived in the servants' building and during the land reform, the estate's holdings were dismantled.