It has just been released that there is conspiracy involving Uchiha Itachi to kill his family. We go back a little to the story..

All is well at first, Itachi has a very normal brotherly relationship with Sasuke. A genius of one of the most powerful clan, he shoulders heavy responsibility/pressure. Everybody sees him as a genius, the burden is tiring, restricting, holding him down. As with all people would know, you would need great strength to change anything. Itachi knows that at the back of his mind, and seeks to improve himself constantly and his efforts are always acknowledged by everyone, but he always finds something lacking. He can't get through that 'something', 'something' limiting him. He tried not to let it bother him. There is only so much one person can accomplish...that was until...

It was a normal mission, where Itachi had to trail a man. Everything is well, when suddenly, Itachi lost sight of the man. It was in broad daylight, in the middle of a small countryside path. He activates Sharingan, and the wierdest thing happened, he can't find the guy using Sharingan! The next moment that guy is standing beside him.

The guy spoke calmly, " Your brother, will be the strongest Uchiha ", after which he disappear.

A few days passes. He starts to wonder, if that guy is speaking the truth, Sasuke can't even activate sharingan yet, he is the strongest Uchiha? Not so much of jealousy, but curiosity, he can't believe or accept how Sasuke is stronger than him! His academic and physical is only slightly more than average. So the one everybody is neglecting, not paying any attention to, is the strongest?

He told his father about it, that Sasuke is going to be the strongest Uchiha, but he shrugged it off with indifference. His father, like everyone else only has his eyes on him alone, not his brother. Imagine what Itachi's mind is going through: Everybody expects he is going to be the succesor of the Uchiha Clan, but the truth is Sasuke is going to supercede him.

As the days go by, jealousy turns to pressure. The successful enlistment into ANBU didn't help, it only adds to the pressure. Itachi trains hard, Sasuke is training too. The gap between them is still great, but Itachi's getting paranoid. A combination of high expectations, and the limits of his power, the prophecy is wreaking his mind. Then we know the rest...