When last we saw Kratos he had killed Ares, the then God of War, and had taken the position for himself with the blessing of Athena who was the Goddess of, amongst other things, the more disciplined side of war. Since then ancient Greece's most angry warrior-become-God has decided that the other Gods of Olympus aren't worth his notice and has set the warriors of Sparta on a crusade of conquest. With Kratos taking over all of the ancient world, the other Gods are getting a bit peeved, as he is warned by Athena, but Kratos isn't bothered by her warnings and decides to enter the fray in the battle of Rhodes.
There then follows a sequence that would be the culmination of most games, but is just the first thing you have to do in God of War II
. As Kratos starts smashing the place up in his giant God state an eagle swoops down, restores him to human size, then animates the Colossus of Rhodes and sets it against Kratos. Obviously one of the Gods isn't best pleased with our anti-hero and has decided to give him a bit of drubbing to make their point. Kratos blames Athena and then returns his attention to the battle. This is where you take over. You must fight your way through the city of Rhodes, attacking the Colossus as you go, until you receive the Blade of Olympus from Zeus, the king of the Gods. This massive sword will enable you to defeat the Colossus, but only if you pour all of your godly powers into it.
Needless to say, pouring his godly powers into a hulking great sword leaves Kratos open to a bit of a backstabbing from the God who has it in for him. After a brief courtesy visit to Hades, Kratos starts out on his quest to avenge himself on the Gods and in doing so help the Titans get revenge of their own. You see, the Titans used to rule the world before the Gods took over, but when his mother stopped Zeus from being eaten by his father Cronos, she allowed the fledgling God to gain in power and topple the Titans from their positions as rulers of the world. However, the Titan Gaia has been watching Kratos and helping him along in various ways, such as letting him get out of Hades again. She now sets him on the path to the Island of Creation, where he can change his destiny if he can confront and defeat the Sisters of Fate.
Being a "six impossible things before breakfast" type of guy, Kratos sets off on his quest. Along the way he will meet most of the great and the good of ancient Greece; Gods, Titans and mortal heroes will be either helped or dispatched as Kratos works his way closer to the Sisters and his eventual confrontation with the Gods. He will also regain much of his power and also collect relics and artifacts that will grant him powerful abilities.