Overview
As a child, Julian Bashir fell behind in school, and was evaluated as having learning difficulties. Because of this, his parents, Richard and Amsha Bashir, had him subjected to genetic engineering. The procedure made him mentally superior to most humans, and greatly enhanced his physical abilities. However, because human genetic engineering is illegal in the United Federation of Planets, Bashir and his parents kept his procedure a secret throughout most of his adult life (DS9 episode: "Doctor Bashir, I Presume?").
Bashir graduated second in his class at Starfleet Medical, having purposely missed a question on his final exam (DS9: "Distant Voices"). He also took "engineering extension" courses during his time there (DS9:"Armageddon Game"). He had his choice of assignments, but chose Deep Space Nine for the opportunity to practice "frontier medicine" (DS9: "Emissary"). He holds the rank of Lieutenant (j.g.) at the time of the series pilot, and Lieutenant from the fourth season premiere until the series finale.
Early on his overly enthusiastic, self-important nature made some members of the crew, such as Miles O'Brien and Kira Nerys, reluctant to spend time with him. However, he eventually becomes friends with O'Brien, Jadzia Dax, and Elim Garak. Bashir falls in love with Jadzia, who goes on to marry Worf. After her death, Bashir joins Worf on a dangerous mission to ensure Jadzia's soul a place in Sto-Vo-Kor.
Bashir's closest friend is O'Brien, and they are frequently shown playing games (like darts) or visiting the holosuite for the recreation of one of several historical battles such as the Alamo or the Battle of Britain. He is also close friends with Elim Garak, with whom he often shares lunch in the Replimat.
During pre-Dominion war tensions, Bashir is kidnapped and sent to a Dominion prison camp and replaced with a shapeshifter ("In Purgatory's Shadow"). His replacement attempts to destroy the Bajoran sun, with the goal of wiping out Bajor, DS9, and a fleet of Federation, Klingon, and Romulan ships ("By Inferno's Light"). The DS9 crew foil the plan, and the real Bashir, along with his fellow captives, shortly thereafter free themselves. The experience (and his outing as a genetically engineered person) began a slow personality change over the course of the series into a much more somber, dark character.
Later, Bashir attempts to integrate several other genetically engineered individuals into Federation culture, with mixed success ("Statistical Probabilities", "Chrysalis").
The covert operations group Section 31 also becomes interested in him and tries twice, unsuccessfully, to "recruit" him ("Inquisition", "Inter Arma Enim Silent Leges").
As depicted in the series finale "What You Leave Behind", Bashir remains aboard Deep Space Nine, and begins a romantic relationship with Ezri Dax.
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