On August 10th, 2010, a.t.b., the Holy Britannia Empire (神聖ブリタニア帝国, Shinsei Buritania Teikoku?) invaded Japan and conquered the country. Japan lost its freedom and rights and was renamed to Area 11, under the control of the Britannia Empire. The Japanese people are called Elevens instead and forced to survive in ghettos, while Britannians live in first world settlements.
A young boy named Lelouch, witnessing the destruction around him, swears to destroy the Britannia Empire, and seven years later, he finally obtains the power to face them and take his revenge.
This anime keeps getting aweosme as the episodes pass. Lelouch is teh shit, nough said about him. I highly reccomend this one if you're fans of series like Full Metal panic in military terms.