(coexisting on another dimensional plane)
Julian Bashir was a Terran slave who joined the Terran Resistance Forces during the Terran Rebellion against the Klingon-Cardassian Alliance in the 2370s. An angry and impetuous individual, Bashir didn't get along well with anyone.
In 2371, Bashir proposed that the rebels destroy Terok Nor in order to prevent Jennifer Sisko from completing a transpectral sensor array which would reveal the rebels' hiding places in the Badlands. Bashir was quite surprised when Benjamin Sisko apparently returned from the dead; he immediately got into an argument with Sisko, who promptly knocked him to the deck. Bashir didn't realize at the time that it was the captain's counterpart from another universe. (DS9: "Through the Looking Glass")
Bashir and Jadzia were lovers; when the Alliance attack on the rebel-occupied Terok Nor was imminent, he and Jadzia took a raider and managed to delay the Alliance's assault by projecting a series of warp shadows to draw off the enemy fleet. After this successful diversion, Bashir returned just in the nick of time to save the Defiant and strafe the Regent's flagship at the Battle of Terok Nor. Smiley was less than pleased at being grateful for Bashir's timely return. (DS9: "Shattered Mirror")
When his lover Jadzia was killed during a skirmish with the Alliance in early 2375, Bashir became even more irritable and unreasonable. He personally shot and killed Vic Fontaine and wanted to torture Ezri Tigan. (DS9: "The Emperor's New Cloak")