Background

      Itachi is the eldest son of Mikoto and Fugaku Uchiha and brother of Sasuke Uchiha of the Uchiha clan who had seen many deaths before the age of five. Even at a young age, Itachi's intellect and talent showed their brilliance in everything he did, as even his teachers said his progress hardly required any help. As a result, he graduates from the Academy at the top of his class at the age of seven, mastered the Sharingan at the age of eight, passed the Chunin Exams at the age of ten, enrolled in ANBU six months later, and became captain by the age of thirteen. In the few battles he’s seen, Itachi was shown to be an incredibly powerful ninja; thus, proving to be a genius above all others and earning praise from allies and foes alike.

      He is also a loving, compassionate older brother to Sasuke of whom he playfully pokes on the forehead whenever he refuses then promises to train his little brother at a later date. Itachi is both Sasuke’s moral support and motivation to improve his skills and techniques – to be just like his brother.
      Itachi has formidable skills as a spy of which he put to use when the Uchiha clan began planning to overthrow Konoha by keeping an eye on the clan and passing the information on to Third Hokage Hiruzen Sarutobi – who ultimately decided to reason with the clan in order to dissuade them from their actions – and Konoha elders. As a result of his spying, Itachi began to act strange, not attend clan meetings, and speak out against the clan itself. Add this to the fact that he was misunderstood; he became the prime suspect for the murder of his best friend Shisui Uchiha who was drowned in the Naka River, but had actually entrusted Itachi with his left eye while the other was taken by Danzo.
      Coupled with orders with orders from Danzo Shimura and the Konoha Council – who found the Hokage’s attempts to negotiate a bloodless end to hostilities between the two parties ineffective – and an agreement from Tobi – who wanted revenge against the Uchiha for turning their backs on him decades earlier – Itachi agreed to slaughter his entire clan overnight, including his friends, superiors, family, and lover. However, before killing his parents, the two people whom he was most hesitant to kill, they stated that they were still proud of their eldest son, and requested that he took care of Sasuke before allowing a tearful Itachi to kill them.
      When Sasuke returned late from a training session, Itachi spared Sasuke because he loved his little brother, and as per the agreement between him and Danzō, did not want to take the life of the person most important to him. He lied to his brother, making himself out as a villain who had killed their innocent family only to test his capacity, and told Sasuke he was not even worth killing. In addition, Itachi told him, "You've always wanted to surpass me. That's why I'm going to let you live… if you wish to kill me, then hate me, despise me… and by all means flee, cling to your wretched life". Itachi also revealed to Sasuke the secret meeting place of the Uchiha, where Sasuke can learn the true history and purpose of the Sharingan. Itachi told him that in order to awaken the Mangekyō Sharingan, Sasuke had to kill the person closest to him, and that when they met again, they should have the same eyes.

     Before leaving the village known as a traitor with hopes his brother would grow strong enough to kill him, Itachi pleaded with the Third Hokage to keep Sasuke safe since Konoha would want his brother dead, and threatened Danzo with revealing everything he knew about Konoha’s secrets to enemy nations if he harmed Sasuke.