Madara Uchiha

Madara Uchiha also known as Tobi in Akatsuki, was formerly Zetsu's subordinate. Madara became a full Akatsuki member after Sasori's death and afterwards wore the same ring as Sasori having recovered it after his death and taking his place as Deidara's partner. After Deidara's death, he revealed his real name and that he had been the one giving Pein orders, making him the true leader of Akatsuki. Only Konan and Pein who were the only Akatsuki members known to have been present at that meeting, Zetsu, and apparently Itachi Uchiha know his true identity. He is one of three people who can use the Mangekyo Sharingan, the other two being Itachi Uchiha, and Kakashi Hatake.

Madara Uchiha is the "founding father" of the Uchiha clan. He was also the first to activate the Mangekyo Sharingan. He had a younger brother, who was equal to him in every way, even possessing the Mangekyo Sharingan, and together they ruled over Uchiha. But eventually Madara's eyes descended into darkness. He did everything he could, but nothing worked. At the bottom of the darkness, he was possessed by the Mangekyo Sharingan. He killed his brother and stole his eyes to activate a new Mangekyo Sharingan that never faded, thus giving him unprecendented power.

He had an alliance with the Senju Clan of the Forest, the First Hokage's clan, and with its leader, the First Hokage, Madara founded Konohagakure. They fought over the laws that should be made in the new village, which led to a battle at the Valley of the End, the battle ending with Madara's defeat, but not death. Madara fled, creating the group Akatsuki. To commemorate the battle, two statues, of Madara and the First Hokage, were carved into the earth around the waterfall. It is for this reason that Naruto Uzumaki and Sasuke Uchiha's fight at that location was noted to be ironic.

Madara created Akatsuki to look over problems. He hid behind the shadows and placed Pein as the figure-head leader, with Madara giving Pein orders from the background. Outside of Pein, the only members who are shown knowing Madara's position as the true leader are Konan, Zetsu, and Itachi.

It has been revealed that Madara did in fact control the demon fox and used it during the attack on Konoha. It remembers and hates Madara for controlling him, and he compares Sasuke's eyes to be as evil as Madara's.

Madara's failure to unleash the demon fox to destroy Konoha made him give up, and so he taught Itachi about the Mangekyo Sharingan and helped him to destroy his entire clan, also teaching him how to unlock its true power. Itachi refers to Madara today as "a pathetic shell of his former self, no longer worthy of becoming the greatest Uchiha."