On the 29th of December 1170, Thomas Becket died, due to a murder, by the knights in the church. But about 8-9 years before he was murdered he was announced the Archbishop Canterbury by Henry II and loved his part of being top class. He was chosen the archbishop as the king didn't feel the punishments were not harsh enough and wanted someone to reform the church courts, so the king announced Thomas Becket to be the archbishop of Canterbury. I reckon there were three people to blame; the knights, the king and himself, Thomas Becket, because in a way, they all did something to cause the death of Thomas.
The first suspect I think was guilty was himself, Thomas Becket. This is because the king ordered this archbishop (Becket) to reform the church courts, but Becket had his other plans and disagreed, by saying, “ the one who stands before you only serves God” and as Thomas Becket refused to do so, the king ended up getting angry.
The second suspect I think was guilty was Henry II. In a way, everyone is involved as Becket did make the king angry. When Henry got tipped over the edge, he said "who will rid me of this troublesome priest?" and while this was being said , the knights were outside the door, listening to his ideas and decided to do exactly what the king had said. I don't think Henry meant it that way as the knights who killed Becket did. Once Thomas was killed, the king said he didn't mean that he should actually be killed and then the day after his death, apparently he walked around the Cathedral whipping his back to say sorry to Thomas.
I also believe that it was the knight’s fault because they did actually kill him. Another point is that they weren't actually ordered to kill Becket, as the king was just murmuring under his breath, and then the knights decided to prove to the king how good they were and went to look for Becket to kill him. The first place they looked was the Canterbury...