The Festetics family and its Chateau have always been the cultural centre of their region, and even occasionally of the whole country. The Festetics family settled in the town of Keszthely in the middle of the 18th Century, and set about improving the economy, science, literature, art and knowledge through their patronage. At the end of the 19th century the family built one of central and eastern Europe's most important architectural landmarks which, together with its landscaped gardens, has blossomed into one of Europe's most beautiful scenes. Keszthely is first documented from 1247. In 1386 a Franciscan monastery and a still standing Gothic church were built. By 1421 Keszthely was being documented as a center for market trading (oppidum).

In 1739 Keszthely was "acquired" by the Festetics family and the town became the nerve centre for the management of their vast estates. First Kristof Festetics founded a hospital, and later Pal Festetics established a school in the town. Then, in 1797, Count György Festetics opened the doors of the Agricultural University, the Georgikon, the Continent's first college fully dedicated to agriculture, and still in operation today. The building of the chateau began shortly after Keszthely became theirs. This is credited to Kristof Festetics, who began work in 1745 building on the ruins of the castle of the previous landowner. Over the coming decades a number of plans for the chateau were drawn up, such as that of Kristof Hofstadter in 1755, which involved the central portion of the chateau. While many of these plans did indeed become reality, the majority remained as just plans. The length of the building was increased to its present day dimensions by the addition of the wings and extra storeys, which were attached in two buildings at the ends of each wing at right angles. The next significant changes were instigated in 1792 by György Festetics. Latterly he invited an architectural consultant, Professor András Fischer from the Vienna Academy, to help with suggestions for finishing the building. György Festetics also employed local craftsmen. Stonemason József Zitterbart laid the foundations of the library, and crafted the door and window frames, windowsills and wells from stone. This fine master even managed to sculpt statues at the same time.

The locksmith work was also performed by a local master craftsman named József Dobrolán, while many of the tiled stoves were the work of the local artisan József Pittermann. The most highly ornamented tiled stoves were placed in the grander rooms. Much of the chateau's original parquet flooring still exists. This, too, was the work of Keszthely master carpenter János Kerbl, who was also responsible for the fittings in the library. The concert hall's light brown oak panelling is decorated with a wide, Baroque edging. The inlaid pattern in this and in the middle section is maple, mahogany and rowan. The ceiling and walls in some rooms were decorated in stucco and were made by Mátyás Vathner from the town of Papa. The chateau of György Festetics' time was the most beautiful building of its age and capable of receiving the most distinguished guests. Significant changes happened after 1883 during the time of Tasziló Festetics. Plans for rebuilding were drawn up by Bratislavan born architect Viktor Rumpelmayer, who at that time was living in Vienna. Rumpelmayer died in 1885 and his work was taken up by architects Gusztáv Haas and Miksa Paschkisch. During the rebuilding new wings were constructed and these were connected to the old parts of the building via towered central section. In front of the main entrance, and supported on four columns, stood a balcony with Baroque wrought-iron railings. The Festetics coat-of-arms was placed in a stone plaque above this.

The Baroque gates were fitted by Bratislavan locksmith Lajos Marton. The fountain and standing vases were works of art by Keszthely locals, builder Antal Hencz and stonemason Máté Polacsek, respectively. The most beautiful and, with its original fixtures and fittings intact, most valuable room in the chateau is the superb library. The first task of Kristóf Festetics after completion of the building in 1763 was the fitting out of the library. This was not just prompted by a desire to collect the arts, but also to protect them: entailing becoming part of ensuring safety of the collection in perpetuity. This is how the much-valued library has been able to remain to this day. The collection of etchings, which is still not yet fully complete, was established by Pál Festetics. The Festetics family never intended the library purely for their own private collections and they tried to put it at the service of the cause of Hungarian culture. György Festetics granted access to the library and lending to the faculty and students of the Georgikon university in Keszthely.

Today books and periodicals number more than 90 000 editions, with an additional 119 manuscripts and four source texts that the library owns. Aside from the decorative library there are 16 rooms that have been fitted out in period furniture. The one-time dining room now hosts concerts of national renown, and the corridor which leads off from there is home to some of the National Museum's most beautiful ornamented weaponry. A separate room houses the Windischgrätz trophy collection. Because of the great number of rare plants, the chateau's grounds are also under special protection. First held in 1817, the annual Helikon festival has become a traditional way of opening the program of the Keszthely summer season. A particular part of this are the Festetics chateau classical music concerts and master classes.