Later it was occupied by several owners in turn, the most prominent being the Hochhauser family, who carried out an extensive reconstruction and converted the castle into a Renaissance chateau.

It acquired its present form with the typical H-shape after two Baroque reconstructions, which took place under the new owners – the Lobkowicz family, when it became the family seat of its Novosedlo-Jezeří branch.

In the Baroque period the chateau and neighbouring countryside formed a unique landscape complex with an area of about 500 hectares. This included a zoological garden, a game park and a formal Baroque garden with water features – cascades and fountains (up to 60 of these structures are listed). In the 19th century an English styled ornamental park was built here and is described as one of the loveliest such gardens of its time.

After the death of Oldřich Felix (1722) the house passed to the main line of the Roudnice Lobkowicz family. Prince Ferdinand Filip Lobkowicz was a great admirer of C. P. E. Bach and patron of Ch. W. Gluck, who played here.

In the early 19th century, Prince Joseph Franz Maximilian Lobkowicz built a theatre in the house and established an orchestra (choir) of 22 musicians. It was at this time that Jezeří became a prominent centre of music. Compositions were performed here by major composers of the time (Vranický, Mozart, Beethoven etc.) Beethoven dedicated a number of his opuses to the prince – his patron: for example, Symphony No. 3, “Eroica”, which had its world premiere at Jezeří. Later a music school was founded here and one of its graduates was the teacher of Antonín Dvořák – Josef Spitz.

After World War II the chateau fell into disrepair and was almost demolished in the mid 1970s due to the coal mining in the grounds. It even disappeared from period maps. However it was saved and has been open to the public since 1996 and its slow reconstruction.

Jezeří Castle is in care of the National Heritage Institute.