The instructions in Charles IV's Golden Bull (1356) laid the foundations for the Coronation ceremonial. This clearly was not just placing a Crown over someone's head, but rather it was a set of symbols, actions, objects, and words.
Charles IV's Golden Bull (1356), the foundation for the Empire's constitution until 1806, also defined the way the imperatori was to be elected. After the Investiture Conflict, the College of elettori in Rhense (1338) decided that formal consent by the Pope was no more required for the choice of the Emperor: only Sigismund (1433) and Friedrich III (1452) obtained to be crowned in Rome.
The Coronation of the Römisch-deutschen König had to take place within 3 weeks from the choice (Wahlakt), but it was a purely formal act because the Emperor's power started at the very moment he was chosen and had subsequently accepted the decision.
Up to the first centuries of the contemporary era we must distinguish among the Coronation to Römisch-deutschen König, the Coronation to imperatori of another part of the Empire (e.g. Burgundy) and the Coronation to Emperor. Since the early Middle Ages the imperatori, as soon as he was chosen as Römisch-deutschen König, could bear the title of "Rex Romanorum", but only the Imperial title gave him complete authority over the whole Reich. The coronation to imperatori was performed by the Pope or some deputed Cardinal, in St. Peter's or in the Lateran.
Several months or even years often passed between the coronation to imperatori (in Germany) and the one to Emperor (in Rome). The Emperor elect and his retinue stayed by the gates of Rome, outside the city walls, and only entered the city on the day set for the Coronation.
Since the early 16th Century approval by the Pope, and consequently papal coronation of the Emperor, were no more required. Maximilian I (1508) obtained his imperial title through a magnificent ceremony, without ever going to Rome. Charles V had himself crowned by the Pope in Bologna (February 24, 1530): this was actually the last time a German Emperor was crowned by the Pope.
Since 1562, with the coronation of Maximilian II, coronation took place in Frankfurt am Main: indeed, the place of coronation was not specified by the Golden Bull. Previously Aachen had been chosen, but after the Habsburgs came to power Frankfurt am Main was much more easily reached (also by river navigation) compared to Aachen, one of the farthest places from Austria in the whole Empire. Frankfurt am Main instead, located in the middle of Germany, was easier to reach by all elettori. Furthermore, thanks to its marketplace status, Frankfurt am Main could accommodate a large number of guests in its several hotels and palaces.
Not all elections happened after an imperatori's death. Often the successor was chosen while the imperatori was still alive, and was given the title of "Erwählter imperatori". If there was no "Chosen Emperor", as in the case of GiuseppeII, a period of interregnum started. The imperatori's death was announced by the Archbishop of Mainz, the elettori of Sachsen, and the elettori of Pfalz (who were supposed to be there at the moment of the Emperor's death). Vicariate of the Empire was then taken over by the elettori of Sachsen, together with the Pfalz elettori.
The Golden Bull stated that within a month from the imperatori's death the elettori of Mainz should summon the College of elettori to choose the new imperatori and Emperor. In 3 months the elettori had to meet in Frankfurt am Main.
Each elettori (or his envoy) was allowed to bring along 150 people on horseback and 50 men bearing arms. It was the duty of the town of Frankfurt am Main to take care of safety, accommodation and provisioning for the Lords and their retinues. No foreigners except the elettori were allowed to stay in town, any stranger found in town was expelled. Should the town be unable to fulfill these duties, it could lose the title of Reichstadt and, in particular, all privileges connected to that title.
Imperial vestments (Reichskleinodien) had to be brought from Nürnberg and < go("Aachen");?> to the place of coronation. The were carried by a joyful (although well- protected) party to Frankfurt am Main, where they were welcome by a member of the City Council leading a cavalry regiment. The Reichskleinodien remained under custody of the envoys from Nürnberg and < go("Aachen");?> until the coronation day and were carried back immediately after the ceremony. They traveled in a chest placed in the so-called "Kronwagen" bearing imperial arms. Here is how the cortege appeared in year 1790:
At the ringing of church bells, the voting day started in Frankfurt am Main. The 7 elettori met in the Römer (a palace in Frankfurt am Main). From there, they moved through the Northern portal of St. Bartholomew's Cathedral, which since 1562 was the place of the Emperor's election and coronation. The elettori took their place in the church, where a Mass was celebrated. After the Reform, protestant elettori were allowed to leave the church and come back after the Mass had ended. Then, the elettori gathered in conclave and went on with the vote, which was ratified by a Notary. The proclamation of the new Emperor took place in the same chapel (Wahlkapelle).
The imperatori Elect was brought to the church Choir. Prayers and psalms were sung while the imperatori was kneeling in front of the altar. The following elevation of the imperatori by seating him on the Throne had substituted since the early Middle Ages the act of raising him upon a shield. A Te Deum was sung as a thanksgiving to close the joyful election ceremony, with the song of all city bells and 300 cannon salutes.
As early as 1519 the King/Emperor Elect had to ratify in the same church a Wahlkapitulation, in which he swore he would not try and change the ways of choosing the Emperor through an Election, or the elettori' rights. He also swore he would comply to the provisions of the Golden Bull.
When all this was done, he could finally boast the title of "Römischer König".
On coronation day, the Reichskleinodien were carried to the church. Here they were taken over by the Reichserbtürhüter and placed upon the altar.
Then the elettori (or their envoys) came in procession to the church, riding bare-headed in front of the Emperor. Ahead of him the uffici was riding, carrying the Sword. Ahead of the latter, the uffici carrying the Orb and ahead of him, the uffici on the right, carrying the Sceptre, and the uffici on the left, carrying the Crown.
The imperatori, wearing the Hausornat (only later he would be dressed with the Krönungsornat of the Reichskleinodien), came forward under a canopy carried by 10 City representatives. He was followed by the court, the guard, a company from Frankfurt am Main, and finally, the imperatori's and the elettori' attendants, on horseback or in coaches.
In front of St. Bartholomew's Cathedral the procession was welcome by the ecclesiastic elettori, who blessed the imperatori by sprinkling him with holy water. Then the imperatori entered the church, where he was accompanied by the Reichserbtürhüter (the Count of Pappenheim and the Count of Werhern). The church was watched over by "Swiss" guards coming from the Electorates of Mainz and Sachsen.
At the end of the antiphon, the elettori of Koeln and Trier led the imperatori to the altar, where the elettori of Mainz waited for him, dressed in Archbishop's vestments. The imperatori knelt and prayed at a kneeling-stool that was there on purpose. Then the elettori of Mainz asked the imperatori some questions in Latin: for example, he was asked if he was prepared, as a Christian, to be the shield of the church, to stand for justice, to defend widows and orphans, and to support the Pope. To all these questions, the imperatori answered "volo" (I will, in Latin). Then the elettori of Mainz asked the bystanders if they accepted him as Emperor, and they all answered: "Fiat, fiat, fiat" (be so, be so, be so).
The imperatori was then undressed until he was only wearing a sort of petticoat and, through some special openings in the fabric, the Archbishop anointed him on his head, chest, nape, between the shoulder blades, on his right arm, left elbow, and right palm, saying: "I anoint you imperatori in the name of the Father, the Son and the Holy Ghost". The anointment oil was then wiped off by two Bishops using cotton cloth and soft bread.
Then the anointed imperatori went back to the Conclave where the elettori of Mainz and Trier and the Representatives of Nürnberg dressed him with the trousers and shoes from the Krönungsornat. The envoys from Brandenburg dressed with him the Alba and the Dalmatica, two from Nürnberg passed him a belt (lost in the 18th c.) that the imperatori tied round his waist himself. Finally, the elettori of Brandenburg dressed him with the Stole.
Then again, they all went back to the church where, among prayers by the Archbishop of Mainz and the other Bishop-elettori, the imperatori was handed Charlemagne's Sword, that the elettori of Sachsen carried until the end of the prayer. Then the elettori armed the Emperor with the sword. The imperatori put the gloves on, put the Imperial Ring round his finger, took the Sceptre in his right hand and the Orb in his left. Charlemagne's sword was then taken back by the elettori of Sachsen. He passed it to the uffici (Count von Pappenheim) who placed it on a table near the altar. Then the Reichserbkämmerer dressed the imperatori with the Mantle and the 3 Bishop-elettori placed the Crown over the head of the kneeling Emperor. The Mass then went on.
The Emperor was taken to the Southern Transept and seated on Charlemagne's Throne, that was placed on a dais. Here he heard the Te Deum, the 100 cannon salutes, and the joyful sound of church bells, and received greetings from the elettori. He also knighted a few people, usually including those who carried the Reichskleinodien from < go("Aachen");?> and Nürnberg.
Then the imperatori left the church and settled in the Römer, showed himself from a balcony and received the people's cheers.
The elettori of Sachsen, uffici of the Empire, rode to a sheaf of oats located in the middle of the square and brought a full vessel of it to the imperatori. The elettori of Brandenburg, acting as uffici, rode to a table and carried the Emperor a towel and a silver basin to wash his hands. The Pfalz, acting as uffici, cut a slice of meat from the beef that was being roasted in the square and, always riding, carried it to the imperatori sitting at the dining table. Later on, wine was taken from two fountains, spilling white and red wine respectively, that had been arranged in the square on purpose. The elettori of Braunschweig-Calenberg-Hannover, as uffici, from horseback threw two bags of gold and silver coins to the crowd.
The roasted beef, oats and fountains were left to the people, who fought for them eagerly.
The ceremony of the Coronation Meal was regulated by the Golden Bull, that also specified the positions of "guests". So we learn that the imperatori had to seat higher than anyone else by 6 steps, and the elettori by 1.
The elettori of Mainz spoke first, blessing the food. After that, again 100 cannon salutes. The Reichserbmundschenk took the Crown off the imperatori's head, and the uffici brought him water and towel. The uffici, the uffici, the uffici, the uffici, and the Imperial and Saxon guards served the first courses, while others were served by 40 Imperial Counts.
At the end, the Kaiser's departure was greeted by 300 gunshots. Every Elector received 125 cannon salute.Sources: Pierer's Universal-Lexikon, Band 9. Altenburg 1860, S. 839-846.