On the website of the municipality of Schwarzau I found a transcript in German, I have translated it in English for you, it mentions several guests:
On October 21, 1911 the last Emperor, then still Archduke Karl of Austria, married his fiancée Princess Zita de Bourbon de Parme in the chapel of the castle Schwarzau am Steinfeld. The night before the wedding we went merrily in Schwarzau. Amongst the people of Schwarzau, feeling very close to the family De Bourbon de Parme, there was much joy and elation. The houses were decorated and festive illuminations were hung in the streets and the gardens. On the eve of the wedding huge fireworks were displayed. The volunteer fire department of Schwarzau appeared in gala-uniform.
A special correspondent reported from Schwarzau: "Today at Noon, in the chapel of the castle in Schwarzau am Steinfeld, the marrriage was held between Archduke Karl Franz Josef of Austria and Princess Zita de Bourbon de Parme. It was celebrated as a family feast without the usual rigid Court-ceremonial. It was no different than when a daughter of a landowner would proceed to the altar and the inhabitants of the nearest towns taking a warm and genuine interest in the celebrations. Around Schwarzau all locations were flagged today. Everywhere simple but well-made decorations greeted the guests. The decorations were mainly twigs and branches between images of the Emperor and of the newlyweds. The access roads were repaired out of precaution, especially for the automobile of the Emperor, coming from St. Egyden. School children were dressed in black Sunday coats and lined the streets, together with catechists and nuns. The groom, Archduke Karl, was waiting impatiently on the Emperor. Meanwhile the Emperor already drove through Schwarzau, where he greeted the people giving him a lively ovation. It was about eleven o'clock when the loud cries could already be heard accompanying the car of the monarch on his journey to the castle.
At the castle, the Emperor was received by the Kapellmeister of the Infantry Regiment Nr 67, Hermann Dostal, performing the Kaiserfanfare. He also wrote the Zita-Walzer on the occasion of the wedding. Shortly after the arrival of the Emperor the main part of the celebrations started in the chapel.
The groom, Archduke Karl, went between between Emperor Franz Josef and his mother Archduchess Maria Josepha of Austria born Princess of Saxony. The bride, Princess Zita, went between the Duke of Madrid, Prince Carlos de Bourbon and her mother the Duchess of Parma born Infanta Maria Antonia of Portugal. Then came King Friedrich August of Saxony and the Heir to the throne, Archduke Franz Ferdinand of Austria. Now the other members of the imperial family as well as other princes and princesses joined. The chapel was decorated in the most festive way, the vestibule was prepared as an entrée, the walls clothed with red damask. Before the altar a red, gold-trimmed damask-covered prie-dieu for the bride and groom, to the left there was a special seat and prie-dieu for the Emperor, covered in yellow damask. Next to the Emperor there was another special seat and prie-dieu, covered in red damask, for Friedrich August of Saxony. All eyes were on the bride and groom: Archduke Karl was dressed in his uniform of the Lorraine Dragoon Regiment, decorated with the Order of the Golden Fleece and the military Jubilee Cross from 1908. The bride, Princess Zita, wore a beautiful dress of ivory satin duchesse, embroided with real silver in a delicate design, the train was covered with Bourbon fleurs-de-lys. The hair was in an updo with a delicate wreath of myrtle and covered by a long bridal veil that felt down to the train and was kept at the head by a magnificent diamond diadem.
The papal Major Domo Gaetano Cardinal Bisletti, the personal representative of Pope Pius X blessed the covenant of the two happy people. After the wedding ceremony Monsignor Bisletti read a personal letter from the Pope. It was also remarkable to mention that Princess Zita spoke a particularly loud "Yes" in front of the altar, however the Princess said this in French: "Oui!". When the wedding guests left to return to their apartments, the newlyweds opened the procession, they were followed by the Emperor sided by the Duchess of Parma, then the Duke of Madrid as head of the House of Bourbon sided by the Archduchess Maria Josepha, the mother of the groom and finally King August Friedrich of Saxony sided with Archduke Franz Ferdinand, the Heir to the throne.
The wedding dinner was held at 13 o'clock in the Thersiensaal of the castle. Five tables were arranged. At the banquet Emperor Franz Josef held a dinner speech in which he spoke to the couple in a most cordial tone. Among other things, the Emperor said: "God save and bless Archduke Karl and Archduchess Zita!". Shortly before the dinner the population of Schwarzau and environment streamed into the park and greeted the Emperor and the bridal couple with enthusiastic cheers and ovations. A chorus of eight hundred school children sang in the park.
It needs to be mentioned that Archbishop Barvona, the Apostolic Nuncio in Austria, has assisted Cardinal Bisletti in the Wedding Mass. On October 19, 1911, the people of Schwarzau organized a torchlight procession in honour of the high newlyweds. The population was visibly proud that this high wedding took place in their small community.
In the school chronicle of the year 1911-1912 the local teacher Mr Karl Mick wrote:
In the school year 1911/12, the pupils from the school as well the Kindergarten took part in the festivities around the wedding in our Most High Imperial House. Because 40 men of the gendarmerie were housed into the school, all lessons were suspended from the 18th to the 23rd of October 1911.
On October 19th 1911, the people of Schwarzau and surroundings gathered in the garden to greet and well-wish the Most High newlyweds Archduke Karl and Princess Zita. Under the leadership of our principal Mr Theodor Gerl the children of the upper classes masterfully performed an exemplary song. Then the principal held a speech to the Most High couple, in which he congratulated the Archduke and the Princess with the forthcoming marriage on behalf of the community. The schoolchildren and all bystanders showed approval to his heartfelt words by loud cheers. Their Highnesses then spoke and expressed their gratitude for the homage ceremony in warm words of praise and recognition.
At the magnificent torchlight procession in honor of the Most High bridal couple also the school and Kindergarten took part. They performed a song for the highest newlyweds and beautifully sang the chorus: This Is The Day Of The Lord, which was recited by the teachers of our district to great example.
On 21 October 1911, the marriage day itself, the school took part in the cooperative church services. On that day His Majesty our beloved Emperor Franz Josef did attend the wedding and the festivities at the castle. The whole village and the school were festively decorated and bedecked. From all directions the crowds flocked together to see the aged monarch (he was 81 years) and to be able to cheer him and the Most High newlyweds. The Schwarzau school marched at top of the imposing procession and also took up a position in front of the main gates of the castle. When His Majesty arrived by automobile, the school children and all those present bursted into roaring cheers. In general, these days were really festive days for our school: our school children saw and heard so much that was quite interesting. For an example: on October 20th early in the morning the well-known domestic aviator (pilot, flyer) Karl Illner came with "The Dove" over Schwarzau, flew over the castle and went in some circles above the Rottal (Red Valley) and landed near the fire station. The rattle of the engine drove the sleepers out of their beds and attracted hundreds of onlookers, including Archduke Karl and the princes. They all wanted to see that most remarkable invention, an aircraft machine. On October 20th a large montgolfière (air balloon) named "Parzival" circled above the castle as a homage to the Most High imperial couple.
