Overview
Leopold Bloom is the fictional protagonist and hero of James Joyce's 1922 novel Ulysses. His peregrinations and encounters in Dublin on 16 June 1904 mirror, on a more mundane and intimate scale, those of Ulysses/Odysseus in Homer's epic poem: The Odyssey.
Factual antecedents
Joyce first started planning a piece in 1906 that he described as "deal[ing] with Mr. Hunter" to be included as the final story in Dubliners, which he later retitled "Ulysses" in a letter to his brother that year. The protagonist of the piece was apparently to be based on a Dubliner named Alfred H. Hunter, who, according to Joyce's biographer, Richard Ellmann, was rumored around town to have been from a Jewish background and to have an unfaithful, promiscuous wife. The same source that related this reputation to Ellmann also suggested that on the night of June 20th, 1904, an intoxicated Joyce approached a young woman standing alone in St. Stephen's Green and spoke to her just before her escort appeared and, feeling Joyce has insulted his date, proceeded to thrash the future author. Sometime after this, according to the Ellmann's source, Hunter appeared on the scene, helped Joyce to his feet, and walked him home. The incident, if accurate, runs parallel to Bloom's rescue of Stephen Dedalus in the closing scene of the Circe episode of Ulysses.
Another Dublin-based model for Bloom, and especially as regards the character's nationalist politics, was the successful entrepreneur and municipal politician Albert L. Altman. Altman owned and operated one of the largest salt depots and distributors in the city during Joyce's entire youth in Ireland and, as noted continuously throughout the period in the Dublin press, was involved in nationalist controversies and Home Rule politics where he was well acquainted with John Joyce, Joyce's father. He was elected to the Dublin Corporation City Council as Usher's Quay Town Councilor from 1901-03 and died in office that final year. Like Bloom, Altman had a son who died in infancy and a father who died by his own hand through accidental poisoning.
Another model for Bloom was undoubtedly Italo Svevo. Svevo was the nom de plume of Hector (Ettore) Schmitz, who was one of Joyce's favorite students when he was a Berlitz English language tutor in Trieste. Schmitz was born and raised a Jew but converted to Catholicism to marry. Joyce had many conversations with him about literature, art, his Jewish background, and Judaism.
From Wikipedia (CC BY-SA 4.0).