Summit War Saga

Whitebeard War Saga, also called "Summit War" Saga (“頂上戦争” 編) on the official website, is the fifth saga in the anime and manga series One Piece. It is also the last saga of the first half of the series. It follows the Straw Hat Pirates, namely Monkey D. Luffy, after their departure from Water 7. A massive war unfolds between the World Government and the Whitebeard Pirates, which was set in motion by the defeat of Portgas D. Ace at the hands of Marshall D. Teach, and climaxing at Ace's execution at Marineford. It is made up of six story arcs.

The Straw Hat Pirates travel to the ghost island of Thriller Bark, where they encounter the Shichibukai Gekko Moriah and recruit a new member named Brook who helps the Straw Hats fight and defeat Moriah. However, upon reaching Sabaody Archipelago they are separated, sent to different parts of the world by Bartholomew Kuma, another Shichibukai. Luffy is sent to Amazon Lily where he befriends Boa Hancock, another Shichibukai who falls in love with him. Upon learning of his brother's impending execution, Luffy makes the difficult decision of rescuing his brother first before reuniting with his crew. Hancock takes him to Impel Down where Luffy breaks in and, upon discovering he is too late, breaks out of the great prison with the aid of Emporio Ivankov with his Okama party and two former Shichibukai, Crocodile and Jinbe. They escape and arrive at the battle at Marineford, with Luffy allying himself with the Whitebeard Pirates. The war ends with the deaths of Ace and Whitebeard, the former breaking Luffy physically, mentally, and emotionally and the latter creating a change in the world forever. After being rescued and taken back to Amazon Lily, he is shaken away from his depression by Jinbe. Luffy decides to train and become stronger with the aid of Silvers Rayleigh in order to go to the New World. However, before doing this, he sends a message to his crewmates that they must become stronger too, and that they will reunite again at the Sabaody Archipelago after two years of training.

Story Arcs

 * Thriller Bark Arc: 2007-2008
 * Sabaody Archipelago Arc: 2008
 * Amazon Lily Arc: 2008
 * Impel Down Arc: 2008-2009
 * Marineford Arc: 2009-2010
 * Post-War Arc: 2010

Trivia

 * This is by far the longest saga of the series, running for 16 volumes, 6 arcs, 156 chapters and 191 episodes.