Schloss Stuppach was in possession of the Walsegg family from 1659 until 1827. Pope Pius VI had actually been a guest in the castle in March 1782 while on his way to Vienna to intercede with the Emperor Joseph II over church matters and attended Mass in a small private chapel within the castle. The castle fell into disrepair after the second world war but has been restored in recent years. One of the servants on the estate died of "acute putrid fever" (possibly typhoid fever) late in 1790 and Countess Walsegg herself succumbed on 14 February 1791. The records in nearby Schottwien parish church relate "On 14 February 1791 died at Schloss Stuppach and was interred here in the family crypt on the 16th the high and nobly born Anna Countess Walsegg, nee von Flammbergin her 20th year, celebrated by me, Mattheus Richter, deacon and priest here". The Count, acting through Franz Anton Leitgib (the fabled grey messenger) and his Vienna lawyer, Johann Sortschan, commisioned the Mozart Requiem and the marble and granite tomb intended as his wife's last resting place. Mozart died before completing the Requiem and Constanze turned to Joseph Eybler and possibly Franz Jakob Freystdler to assist with completion. Franz Xaver Sussmayer was eventually entrusted with the task and contributed the several passages. It is believed that he composed the Sanctus, Benedictus and Agnus Dei entirely and a claim made years afterward that there may have been scraps of paper to assist with these three passages is inplausable. The Lacrymosa passage by Sussmayer, the final passage in the 13th century Dies Irae prayer by Thomas of Celano, occupies five pages while Mozart had earmarked four for this item. The completion of the Requiem is a complicated and controversial matter about which there is still much division.
