Born on July 8, 1965, Dr. Daniel Jackson is an only child and an orphan. His maternal grandfather and only living relative, Nick Ballard (played by Jan Rubes), was a noted archaeologist and too busy to take the orphaned Jackson under his wing. (Crystal Skull). Daniel's parents, Melburn and Claire Jackson, also archaeologists, were crushed while supervising the placement of a piece of Egyptian art in the Metropolitan Museum of Art (The Gamekeeper). His grandfather abandoned him after the funeral. Though placed in foster care, Daniel visited his grandfather in a mental institution until they had an argument over Daniel's failing career and Daniel left.

Daniel is an archaeologist and linguist who speaks more than twenty-three languages (1969) (in another episode, the number is given as twenty-seven (200); on-screen, he has been shown speaking English, Ancient Egyptian, Spanish, Latin, Russian, Mandarin Chinese and German, as well as Goa'uld, Ancient, and Unas (which he decoded).

In the film Stargate, Daniel first appears speaking at an academic seminar, where he finds little acceptance of his theory that the Pyramids of Giza were much older than they were thought to be. Only one person, an aged woman named Catherine Langford, remains in the audience, and she offers him a job. For Langford, Daniel uses his knowledge of ancient Egypt to open a device called the Stargate, by interpreting the cover-stones found with it, realizing that the symbols which everyone assumed were hieroglyphs were actually constellations. On the original mission through the Stargate to the planet Abydos, Daniel meets, marries, and falls in love with, a native woman, Sha'uri (she is named Sha're in the TV series Stargate SG-1). After winning the battle to free the Abydonians from the System Lord Ra, Daniel decides not to return to Earth with the rest of the team and instead live the rest of his life learning about the culture and history of Abydos with its insights into ancient Egypt. Jack O'Neill lies in his report and says that Daniel Jackson is dead, and Daniel assures Jack that they will bury their stargate on Abydos.

In the television series Stargate SG-1, Daniel's life changes when his wife and his brother-in-law are abducted; Daniel joins the Stargate team SG-1, to recover Sha're. Over the course of the series, Daniel has been captured, infected with alien viruses, suffered the implantation of a dozen alien consciousnesses within him, has died and returned to life many times, and has ascended to a higher plane of existence twice.

Daniel is briefly reunited with Sha're/Amonet when she temporarily controls her body while pregnant with the Harsesis child Shifu in the season 2 episode "Secrets". Sha're dies in the season 3 episode Forever in a Day, when Teal'c kills her to prevent Amonet from killing Daniel. As Amonet tortures Daniel, Sha're manages to send him a message, asking Daniel to find her child, to forgive Teal'c for killing her, and she reconfirms her love for him. Daniel nevertheless remains a part of the team and later saves Skaara from the Goa'uld Klorel in Pretense. Daniel journeys to a planet called Kheb to search for the Harcesis. He discovers the child is being cared for by Oma Desala, a being of great power and wisdom, and accepts her custody in the episode Maternal Instinct, because she can keep him free of the Goa'uld better than he can.

In the episode "The Curse", the death of Daniel's old professor and mentor leads to an awkward reunion with his ex-girlfriend, Sarah Gardner. This also led to the discovery that his professor had acquired a Goa'uld artifact containing the dormant Goa'uld Osiris, which possesses Sarah. Daniel meets her again in season 5's "The Summit"/"Last Stand". Shifu returns, much older, to teach Daniel the dangers of the full knowledge of the Goa'uld in the episode Absolute Power, by showing him a vision of what he would become if he used the Goa'uld knowledge. In this vision, Daniel, overcome by the evil nature of the Goa'uld knowledge, takes over the planet, imprisons Sam for questioning his authority, destroys Moscow, and apparently causes Teal'c's death.

In the episode Meridian, Daniel Jackson dies after exposure to radiation while attempting to fix a naqahdriah reactor; attempts to cure him with Goa'uld healing devices initially fail. However, Daniel does not perish completely; instead, he ascends to a higher plane of existence, guided by the Ancient Oma Desala. While Ascended, Daniel is replaced in SG-1 by Jonas Quinn, a native of the planet that Daniel gave his life to help, although the rest of the team (particularly Carter and O'Neill) find it hard to get over Daniel's absence. As an Ascended being, Daniel visits SG-1 on occasion, but he is not allowed to interfere, according to the laws of ascended beings. In the episode Abyss, he offers Col. Jack O'Neill ascension as a means of escaping Ba'al's torture, but O'Neill declines. In The Changeling, Daniel helps a delusional, injured Teal'c to return to reality after he is fatally injured and shares his symbiote with Bra'tac, whose symbiote has been killed, by playing the role of a psychologist in the delusion.

In the season 6 finale Full Circlue, ascended Daniel seeks to defeat the plans of Anubis by having SG-1 locate a device called "The Eye of Ra", which is on Abydos. The plan fails. Daniel attempts to make a deal with Anubis to safeguard the lives of the Abydonians and SG-1, but Anubis breaks his word. Daniel tries to destroy Anubis, only to be whisked away before doing anything, and Abydos is destroyed, although Oma helps Daniel by Ascending the entire population of Abydos before they are killed.

Eventually, Daniel is discovered on the planet Vis Uban in the episode Fallen, having violated the rules of ascended beings, which forbid interference in the lives of humans. As punishment, he is returned to human form with total amnesia, but he recovers his memories of his corporeal life rapidly, and rejoins SG-1 full-time, while Jonas returns to his people. Daniel can tap into some of his memories of his time of Ascension in Orpheus. Daniel spends much of Season 7 trying to find the Lost City of the Ancients, which allows him to rescue Sarah when Osiris tries to trick him into revealing the location of the city (Chimera). This event leads to the discovery of the Ancient Outpost at Antarctica in the Season 7 finale Lost City.

Daniel dies again in Reckoning (Part 2), killed by RepliCarter after he is captured while attempting to recover his memories of Ascension. Daniel uses the link between them to halt all Replicators in the universe long enough for them to be destroyed, providing his friends with the crucial time they need to prepare the Dakara Superweapon. The next episode, Threads reveals that Oma Desala is providing a path for Daniel to Ascend. But as he prepares, Anubis appears. Daniel persuades Oma Desala to fight Anubis (As the two are equally matched, Anubis can never escape as long as Oma fights), and Daniel is Descended back to Earth naked to live on as a human, this time with full memory of what just happened to him.

In the season finale, Moebius, Daniel inherits many items from the Langford estate, including a book with depictions of Ra with a ZPM. SG-1 goes back in time and involuntarily begin the original Earth rebellion against the Goa'uld. Daniel is the only one to survive, and he helps an alternate SG-1 team devise a plan to free Ancient Egypt and restore the timeline. After the plan succeeds, Alt-SG-1 and Daniel must live out the rest of their lives in Ancient Egypt, and a variation of the original timeline is restored.

In the Season 9 opener Avalon, Vala seeks out Daniel at Stargate Command. Needing his linguistic skills, she uses a bracelet to bind them together for a treasure hunt on Earth and thus prevents prevents him from going to Atlantis. The discovery of an Ancient communication device transports Vala's and Daniel's mind to a village in a distant galaxy where they make contact with the Ori and unintentionally bring that threat to the Milky Way. Vala and Daniel return to Earth safely. As the season draws to a close, SG-1 and several other ships descend upon an Ori supergate, and attempt to destroy it. They are defeated, however, and Daniel rings away just before his ship is destroyed.

In the season 10 opening episode, Daniel finds Vala aboard one of the invading Ori ships. He is also confronted by Vala's rapidly maturing daughter, Adria, who almost kills him. After the escape of Daniel and Vala, Daniel speaks up in support of Vala's request to join the SGC. Shortly thereafter, Daniel attracts the attention of Adria, who hints that the Ori have plans for him. During The Quest, the team discovers Merlin in suspended animation. Merlin dies during his attempt to build another Sangraal (a device to destroy ascended beings), but transfers some of his knowledge and powers into Daniel. Using these, Daniel begins to build another Sangraal, but the Ori attack and Daniel must force his friends to escape before the weapon is completed, leaving him behind to be captured by Adria. In the episode The Shroud, Daniel is turned into an Ori Prior by Adria to convert the Tau'ri to the path of Origin. At the end of the episode, Daniel has returned to his normal self. In Unending, the last episode of the series, SG-1 gets stuck in a time dilation field aboard the Earth ship Odyssey, and a romance between Vala and Daniel comes to fruition. Before the time dilation field is reversed after fifty years, erasing all linked memories in the process, Daniel and Vala express their feelings for each other.

Source | Wikipedia.org