Created by Batman to survey the metahuman population in the absence of leadership from Superman and Wonder Woman, the Brother MK I surveillance satellite was given intelligence by Alexander Luthor and abducted from Batmans control by Maxwell Lord.
Under Maxwells instruction, Brother Eye began spreading the OMAC virus through the civilian population to form an OMAC army in Maxwells own plans to control the metahuman population.
During the Infinite Crisis, Brother Eye sends the OMAC army to kill the metahuman population after Wonder Woman kills Maxwell Lord. Batman leads a collection of heroes to hunt down Brother Eye, destroying its guidance system and sending it plummeting to Earth.
Surviving Batmans attack by downloading itself into a secondary hub in the Gotham sewers, Brother Eye becomes a pawn of Brainiac; using its recreated OMAC army to serve Brainiac in attacking Gotham City.