The 2401 reawakening of Data in a synthetic body found on Daystrom Station, where Data won control over Lore and the other minds held inside it.
The android body found at Daystrom Station in 2401 was a synthetic golem built by Altan Inigo Soong. It held the memories of several of the androids created by the Soong family, including Data and his evil brother Lore. At first Lore was in control.
Data fought Lore from within, helped by his old friends, and finally took over by absorbing his brother. With his mind restored, Data was able to rejoin Geordi La Forge and the rest of the old Enterprise crew for the defense of Earth.