|Full Name||♂️ Otto Mahler -|
|Birth||#1||Date of Birth||18-06-1873|
|Place of Birth||Jihlava|
|Siblings||♂️ Isidor Mahler, ♂️ Ernst Mahler, ♂️ Karl Mahler, ♂️ Rudolf Mahler, ♂️ Arnold Mahler, ♂️ Friedrich (Fritz) Mahler, ♂️ Alfred Mahler, ♂️ Konrad Mahler, ♀️ Leopoldine Quittner-Mahler, ♀️ Justine (Ernestine) Rose-Mahler, ♂️ Alois (Louis) Mahler, ♀️ Emma Marie Eleanor Rose-Mahler, ♂️ Gustav Mahler|
|Date of Marriage|
|Death||#1||Date of death||1895|
Relation to Gustav Mahler (1860-1911): A brother.
- Born: 18-06-1873 City of Jihlava.
- Father: Bernard Mahler (1827-1889) Previous generation.
- Mother: Marie Mahler-Herrmann (1837-1889).
- Brothers and sisters:
- Isidor Mahler (1858-1859).
- Gustav Mahler (1860-1911).
- Ernst Mahler (1862-1875).
- Leopoldine Quittner-Mahler (1863-1889).
- Karl Mahler (1864-1865).
- Rudolf Mahler (1865-1866).
- Alois (Louis) Mahler (1867-1931).
- Justine (Ernestine) Rose-Mahler (1868-1938).
- Arnold Mahler (1869-1871).
- Friedrich (Fritz) Mahler (1871-1871).
- Alfred Mahler (1872-1873).
- Otto Mahler (1873-1895).
- Emma Marie Eleanor Rosé-Mahler (1875-1933).
- Konrad Mahler (1879-1881).
- Education: School Boys Primary (Jostova Nos. 2/5, Obere Elkergasse No. 119), City of Jihlava.
- Education: 1883-1886 School German Gymnasium (Hluboka street Nos. 1/109, Nonnengaschen 608), City of Jihlava.
- Education: Conservatory of Vienna, City of Vienna.
- Profession: Composer.
- Address: Jihlave House Gustav Mahler Jihlava 1872-1889 (Znojemska street Nos. 6/1088, Pirnitzer Gasse No. 264), City of Jihlava.
- Address: Vienna: House Ludwig and Leopoldine Quittner - Wallensteinerstrasse No. 7 (1889). He lived with Leopldine and her family during his first year at the Conservatory of Vienna.
- Address: Vienna: 1890-1902 House Gustav Mahler Vienna - Breitegasse No. 4.
- Died: 06-02-1895 Vienna. Aged 21. Suicide. Shot himself in the head, leaving a note saying that life no longer pleased him so he "handed back his ticket". Commits suicide in the apartment of Nina Hoffmann-Matscheko (1844-1914) in Vienna. On 06-02-1895, Otto is as usually at Nina Hoffmanns. Around 16.30 hours he leaves the apartment - at least, he pretends, because he enters an adjoining room, lays himself on a armchair and shoots himself in the heart. A doctor called can only determine death. Gustav Mahlers reaction is not recorded in any of his letters. His motivation remains unknown, though the 'Illustrierte Wiener Extrablatt' speculated about a 'matter of the heart'. According to Gustav's widow Alma, Otto's suicide-note stated that life no longer pleased him, so he 'handed back his ticket'.
- Otto leaves 77 crowns just enough to pay the funeral. The funeral is arranged by Emil Freund and a notary from Jihlava. They signed all the documents.
- Buried: 10-02-1895. Central cemetery, Cemetery 4: Old Jewish cemetery (Gate 1), T1 - Group 20, Row 19, Grave 35 (or No. 25). Vienna. Destroyed in Second World War. Fragments moved near new plaque.
- Year 1873: Otto is 13 years younger than his brother, Gustav Mahler (1860-1911).
- Year 1888: At the age of fifteen he was admitted to the Conservatory of Vienna (Anton-von-Webern-Platz No. 1) but left of his own volition in april Year 1892. Justine (Ernestine) Rose-Mahler (1868-1938) and Natalie Bauer-Lechner (1858-1921) kept the news from Gustav, who was furious.
- Year 1889: Otto is 16 years old when his mother, Marie Mahler-Herrmann (1837-1889) dies.
- Year 1890: Summer holiday with Gustav Mahler.
- Not in the army because of a half blind left eye.
- Year 1892: Leaving the Conservatory.
- Year 1893: A composition by Otto Mahler on texts of Hans Emanuel Sax.
- Year 1893: Lived with his sisters Justine (Ernestine) Rose-Mahler (1868-1938) and Emma Marie Eleanor Rose-Mahler (1875-1933).
- Year 1894: Gustav Mahler made efforts to find a suitable position for Otto. Posts in neither Bremen nor Leipzig were successful, and by the end of Year 1894 the situation was becoming desperate. In Leipzig Chorus Master of the Neues Theater.
- Gustav Mahler asks him to become his archivist.
- Year 1895: Justine (Ernestine) Rose-Mahler (1868-1938) was hearing "unpleasant" news: "Otto is alarmingly thin; in the course of this, I can't help thinking of Hans Rott (1858-1884), and one can't do anything".
- Year 1895: Suicide.
- He left two symphonies,
Manuscript first three movements of Anton Bruckner (1824-1896) - Symphony No. 3
- Gift of the autograph from Anton Bruckner (1824-1896) to Gustav Mahler (1860-1911).
- Year 1894: Gift from Gustav Mahler to Otto Mahler (1873-1895).
- Year 1895: In a locked black trunk together with letter from Gustav Mahler to Otto Mahler return to Gustav when Otto Mahler died.
- Year 1908: Gustav Mahler asked Alma Mahler (1879-1964) to check if the manuscript was still ther. Case was unopened for 13 years.
- Year 1911: From Gustav to Alma Mahler (1879-1964) (widow).
- 1939: Alma Mahler tried to sell the maniscript to the nazi's.
- 1940: The bulky Bruckner manuscript was one of the very few possessions carried in Alma's backpack during her daring 1940 escape over the Pyrenees with her third husband, writer Franz Werfel, avoiding Vichy France border patrols.
- 1945: A trunk containing Otto's effects, including his compositions and, perhaps, Mahler's letters to him, was destroyed when a bomb hit Alma Mahler (1879-1964)'s house towards the end of the Second World War; according to Alma, Mahler had been afraid to open it.
- Alma Mahler sold everything left to the National Austrian Libary for 32.000 Swiss Franc.