At the onset of 44 BC, the honors heaped upon Caesar continued and the subsequent rift between he and the aristocrats deepened. He had been named 'Pater Patriae' or Father of the Country and Dictator Perpetuus or Dictator for Life. This title even began to show up on coinage bearing Caesar's likeness, clearly placing him above all others in Rome. Some among the population even referred to him as 'Rex' for King, but this Caesar refused to accept, at least publicly. At Caesar's new temple of Venus, a Senatorial delegation went to consult with him, and Caesar refused to stand to honor them upon their arrival. Though the event is clouded by several different versions of the story, it's quite clear that the Senators present were deeply insulted. He attempted to rectify the situation later by exposing his neck to his friends and saying he was ready to offer it to anyone who would deliver a stroke of the sword. This seemed to at least cool the situation, but the damage was done. The seeds of conspiracy were beginning to grow.
The fear of Caesar becoming King continued when someone placed a diadem (crown) on the statue of Caesar on the Rostra. The tribunes, Gaius Epidius Marcellus and Lucius Caesetius Flavius removed the diadem, and Caesar's reaction was one of displeasure, though he did nothing about it at the time. It's difficult to determine Caesar's exact position on the matter, but it seems quite likely, that many public events like this may have been staged to gauge the reaction of the people. This too, would begin to build a common perception that Caesar was King even without the title, perhaps making the eventual transition from Republic to monarchy less difficult. Not long after the incident with the diadem, the same two tribunes had citizens arrested after they called out the title 'Rex' to Caesar as he passed by on the streets of Rome. Now seeing his supporters threatened, Caesar acted harshly. He ordered those arrested to be released, and instead took the tribunes before the Senate and had them stripped of their positions. Caesar had originally used the sanctity of the Tribunes as one reason for the start of the civil war, and now hypocritically revoked their power for his own gain.
At the coming festival of the Lupercalia, the biggest test of the Roman people for their willingness to accept Caesar as King was to take place. On February 15, 44 BC, Caesar sat upon his gilded chair on the Rostra, wearing his purple robe, red shoes and a golden laurel. Armed with the title of Dictator for Life, and with his rather kingly appearance, it seemed the right time to stage a public display. After the race around the pomerium that was a tradition of the festival, Marcus Antonius ran into the forum and was raised to the Rostra by the priests attending the event. Antony produced a diadem and attempted to place it on Caesar's head, saying "the people offer this (the title of King) to you through me." There was, however, little support from the crowd, and Caesar quickly refused being sure that the diadem didn't touch his head. The crowd roared with approval, but Antony, undeterred attempted to place it on Caesar's head again. Still there was no voice of support from the crowd, and Caesar rose from his chair and refused Antony again, saying, "Jupiter alone is King of the Romans." The crowd wildly endorsed Caesar's actions, and it was quite obvious that they weren't yet ready for a king. The event, likely staged may have had two political motivations. First, had the crowd supported Antony, Caesar may very well have accepted, and perhaps the true intention was a simple test of the people. Another theory is that Caesar wanted a massive public event to be able to declare that he didn't want the title, and perhaps mend fences with the Senate. Either way, it was quite clear that the common citizens weren't ready.
All the while Caesar was still planning a campaign into Dacia and then Parthia. The Parthian campaign stood to bring back considerable wealth to Rome, along with the potential return of Crassus' lost standards. Conquest of Parthia would not only further inflate Caesar's legendary status, but may be just the sort of popular agenda that would make the idea of a Roman king acceptable. Caesar planned to leave in April of 44 BC, and the secret opposition that was steadily building had to act fast. Made up mostly of men that Caesar had pardoned already, they knew their only chance to rid Rome of Caesar was to prevent him ever leaving for Parthia.