[1][2][3] The History of the Expedition includes the text of a letter sent by Cardinal Henry of Marcy to the nobility of Germany enjoining them to attend the "court of Jesus Christ" (curia Jesu Christi).
[4] The Curia Christi was called to deal with two issues: the conflict, internal to the Empire, between the emperor and the archbishop of Cologne; and the fall of Jerusalem to the Ayyubids.
The conflict between emperor and archbishop has been traced to Frederick's privileging the cities of Aachen and Duisburg at the expense of the economy of Cologne.
Open conflict began when Philip refused to allow an imperial army to cross his territory and Frederick responded by imposing an embargo on Cologne on 25 July 1187.
Urban's successor, Gregory VIII, threw himself fully behind a new crusade and moved quickly to resolve his differences with the emperor.
According to a letter sent by Rabbi Moses ha-Cohen of Mainz to his brother-in-law, Eleazar of Worms, a mob gathered in the marketplace intending to invade the Jewish quarter on 26 March (Sabbath).
After the diet, on 29 March, Frederick and Rabbi Moses rode together through the streets of Mainz to demonstrate that the Jews had imperial protection.
[6] Following the submission of Philip, a letter concerning the fall of Jerusalem was read to the assembly and Bishop Godfrey of Würzburg preached a crusade sermon.
To prevent the crusade from degenerating into an undisciplined mob, participants were required to have at least three marks of funding, enough to support oneself for two years.
[6] In a separate piece of business, the Curia Christi summoned the disgraced Henry the Lion to attend the diet of Goslar (25 July–8 August 1188).