The Uchiha clan (うちは一族, Uchiha Ichizoku) is one of the strongest clans that are currently present throughout the world, rivaling in power only to the Senju clan and Uzumaki clan. The Uchiha are led by Madara Uchiha and wield the mighty Dōjutsu, the Sharingan.
The Uchiha clan descended from the elder of the two sons of the Sage of the Six Paths. The elder brother inherited the Sage's "eyes", powerful chakra and spiritual abilities. When it came time for the Sage to choose a successor, he questioned the two on what course of action they would follow to bring order to the world. The elder believed that power was the way to bring peace, while the younger believed love was the way. The Sage favoured the ideal of the younger brother, and therefore designated the younger as his successor, causing the elder to be filled with jealousy and hate. From this hate came what Tobi calls the Curse of Hatred (憎しみの呪い, Nikushimi no Noroi). From the younger son descended the Senju clan who would be the eternal rivals of the Uchiha.
Before the founding of the ninja villages, the Uchiha were one of the many mercenary clans for hire. Because of their Sharingan, the Uchiha clan came to be known as one of the two strongest clans, the other being the Senju clan. Madara Uchiha was particularly powerful, and, upon attaining the Mangekyō Sharingan, he took control of the clan. Under his leadership the Uchiha grew stronger, conquering whatever clans they came upon, such that, whenever the Uchiha clan was hired for a job, the opposing side would hire the Senju, and vice versa.
Main article: Naruto: Path of our Heroes