Mukesh: Chairman, Reliance Industries
Ambani: Chairman, Reliance ADA Group
Why they matter: These billionaire brothers from India are locked in a bitter intrafamily rivalry, and each seems intent on leading the group of companies he inherited from their late father in a different direction.
Elder brother Mukesh is building one of the world's biggest oil refineries and has embarked on a bold plan to revolutionize Indian agriculture. Not to be outdone, flashy younger brother Anil is building one of the world's biggest power plants using clean-burning natural gas. He has also created Reliance Communications, the world's fastest-growing CDMA mobile-phone network, and has announced plans to invest billions in India's enterprise broadband network. Imagine what these two could do if they just saw eye to eye.