The magnificent Spanish Hall, the Rudolf Gallery and other premises were built by Rudolf II from 1602 to 1606 to store his art collection. The largest ceremonial space at Prague Castle, it measures 47 m by 24 m, and its richly stuccoed ceiling is 13 m high. The hall is not open to the public – it’s used primarily for ceremonial functions, large presidential receptions, and concerts.
Spanish Hall is a part of the Prague Castle representative premises located in the Northern wing towards Prašný most (Powder Bridge). The hall got its name from being built above the stables of noble Spanish horses, the cult of which Rudolf II keenly pursued. It was built in the beginning of the 17th century upon the wish of Rudolf II to store his collections of statues. It is magnificent due to its parameters – it is 43 m long, 21 m wide, and 12 m high. When the Spanish king Filip II visited Prague, he decorated Rudolf II by the Spanish order of the golden fleece, and its plaster model is hung on the hall’s window. The author is probably Giovanni Maria Filippi. Originally, there were pillars in the middle of the hall, and a painted ceiling. The hall was vaulted only in the Baroque era; Kilián Ignác Dientzenhofer gave it a straight, higher ceiling. In the second half of the 18th century, the so called arch hallway was created around the hall, which caused the bricking-in of the windows on this side. In place of the original windows, J. A. Saeckel painted illusive garden vedutas. The hall was re-built on the occasion of Ferdinand V coronation (1836), when royal balls were held in the Spanish hall and in the adjacent hall. New floor of oak parquettes was laid, ceilings were painted in light tones by Josef Navrátil, and candles in new chandeliers reflected light from eight newly set large mirrors. Later on, the hall was re-built again for the prepared but never realized coronation of Franz Joseph I in a pseudo-Baroque style by Ferdinand Kirschner. The statues of Science, Industry, Trade and Arts were settled here, from the author A. P. de Vigne. Part of the stucco decoration on the walls dates back to the era of Rudolf II.
The Spanish Hall, Rudolf’s gallery, and some other premises too were full of art treasures Rudolf II passionately collected or was given as a gift. However, most of them were taken to Sweden as a war booty, or as Habsburg royal property to Vienna, when the seat of Emperor Matthias II was transferred there, lots of objects from the collections were sold for ridiculous money. Part of the collection which remained in Prague now forms a part of the exhibition in the Prague Castle Picture Gallery.
Source: https://www.prague.eu/en/object/places/409/prague-castle-spanish-hall-spanelsky-sal