Jake Sisko was the son of the famous Starfleet Captain Benjamin Sisko and Jennifer Sisko. He chose not to join Starfleet, instead becoming a writer. He was close friends with Nog, who would later became the first Ferengi in Starfleet. (DS9: "Emissary", et al)
In 2384, he had a child with Korena that they named Benjamin after his father, though they frequently called him "Benny". Around this time Jake started to suffer from nightmares where he was alone in an empty white space. They usually occurred in the period around the date of his father's death.
In 2394, after the nightmares got worse over several years and he started to hear his father calling his name, Jake agreed to attend the Festival of Tears as a guest of the Kai. He hoped that it would dispel any issues he had over his father's death and free him of the dreams. During the festival he had an orb experience where he was told by the Prophets and his father to bring about the prophesied Reckoning
Following the path set out in his vision Jake undertook an expedition to the caverns under the ruins of B'hala with a guide. They discovered the Reckoning Tablet where Jake was again given a vision by the Prophets telling him to bring about the Reckoning. After leaving the caverns Jake was taken into custody by Bajoran Security and transported to Gateway Station for questioning by the Dominion.
Despite his wishes not to be involved in the various plots by Weyoun to denounce the tablet as a fake and those by Kira Nerys and Kai Winn to retrieve the tablet and return from the station to Bajor, he was convinced to become involved in the latter.
During a dinner with Weyoun Jake broke the tablet in a fit of rage and freed the trapped Prophet and Kosst Amojan setting the Reckoning in motion. He later gave himself to the Prophet as its instrument for the battle following the death of Kira b the Kosst Amojan possessed Dukat.
Following the defeat of Dukat, Jake was transported to the Fire Caves on Bajor. There under the Prophet's control he sent Dukat's body into the flames before the Prophets "sealed the fate" of the Pah-wraiths.