Caesar was assassinated on the 15th March, 44 BC. He was seen to have grown into a tyrant, and so although it did not justify his killing, it did make it ‘acceptable’ to an extent. We still hold this view in contemporary society; think of the treatment with Colonel Gaddafi in 2011.
Once Caesar was stripped of his tunic, there are varying sources as to how many conspirators stabbed him. Appian believed there to be 15, Plutarch and Livy thought 23, Suetonius thought 60+, and Nicolas of Damascus thought 80+. Most accounts today agree with the figure that Suetonius proposed.