sentences:  Some of the electors were won over to the cause of the pope; a new embassy was organized; and in February, 1447, shortly before the death of Eugene, the four Bulls constituting the Concordat of the Princes was promulgated.In February, 1448, a complete agreement was reached in the Concordate of Vienna, concluded between Frederick III and Nicholas V.
  
  Gregory, who had considered even the declaration of neutrality an ignoble concession, was disappointed at this turn of events and decided to abandon ecclesiastical politics.During the negotiations between the pope and the electors there appeared the anonymous "Admonitio de injustis usurpationibus paparum" or, as Matthias Flacius entitles it, "Confutatio primatus papæ", which is generally ascribed to Gregory.