Italian by nationality, he always claimed his roots were Slavic and often spoke of having Croatian ancestry.
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'He proudly admitted his Croatian ancestry. "You can say ‘di anima Slav, di cultura Austriaca…’ I’m of Slavic origin and still a bit of a Slav," he confessed to Dominic Gill in a 1973 interview. "I’m certainly not Latin." Slav or not, he is said to have felt less at home in Italy than in Austria, which he called "my country"'.

It is said that he claimed to be a descendant of Jacopo dei Benedetti—aka Jacopone da Todi—the 13th-century Umbrian poet (c. 1230 – 25 December 1306).  Benedetti Michelangeli created a 'descent from an ancient lineage, which redeemed the grey reality of a lower-middle-class family with a father and mother who were unemployed and had limited economic means.'

The other branch of AMB's "family romance" dates back to the 1970s, after Benedetti Michelangeli had disdainfully abandoned Italy. In interviews, he stated that his family was of German origin, Benedikter. He also said he had been a bomber pilot during the war. It seems clear that in this case, Benedetti Michelangeli was "appropriating" his father's wanderings with the South American diplomat and making his dream of military glory realistic. [Orphaned at an early age of both parents, Giuseppe had been tutored by a South American diplomat who had taken him with him to the various countries where he served.]  (Piero Rattalino)
 
His father, who was a count and a lawyer by profession, was also a musician and a composer and began teaching music to Benedetti Michelangeli before he was four years old.  Michelangeli learned to play the violin at the age of three and would later study the instrument at the Venturi Institute in Brescia, before switching to piano under Dr. Paolo Chimeri, who accepted him into his class following an audition. 
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At home, in an environment dominated by an innate predisposition and keen interest in music, little Ciro – as Arturo was called for some of his curls which made him resemble Cirillino, a then well-known character in Corriere dei Piccoli – began studying the piano at three years of age, under the guidance of his father.
 
At four years of age, Arturo gained admission to the Venturi Civic Institute of Music in Brescia, as a pupil of maestro Paolo Chimeri, and at seven years of age, on 10 March 1927, he aroused general amazement and admiration when he performed for the first time before an audience, during the recital marking the end of the 1925-26 two-year course of studies.

Michelangeli once said: "I learned everything I know from Paolo Chimeri."
(GUIDETTI, Giuliana. Vita con Ciro. Palermo: L’Epos, 1997)
 
In the spring of 1929 he attended private lessons with maestro Giovanni Anfossi in Milan, where his mother accompanied him each week.  Anfossi was a teacher at the Collegio Reale delle Fanciulle and owner of his own school.

Giovanni Anfossi was a descendant of the famous opera composer of the Neapolitan school Pasquale Anfossi (1727-1779), who became famous throughout Europe for his comic operas. Giovanni founded a music institute in Milan named after his descendant and devoted his entire life to piano pedagogy. His numerous students included Luisa Baccara, a Venetian pianist, lover of the poet Gabriele D’Annunzi, with whom she lived in close proximity until his death.

He took the piano license exam at the Giuseppe Verdi Conservatory in Milan in the fall session of the 1930-31 school year; at the same conservatory, he took the diploma exam privately on 12 June, 1934 (at only 14 years of age), obtaining scores ranging from 6 to 10 in the various tests, with an average of 8.50. The program for the actual performance exam, graded 10 and including the first book of Brahms's Paganini Variations on a Theme, Op.35 [see below for ABM's idiosyncratic way with them] and Ravel's Jeux d'eau demonstrate that fourteen-year-old Benedetti Michelangeli was a complete pianist.  (Piero Rattalino)

'His failure to attend public school—piano and violin lessons at the Venturi Institute in Brescia were, obviously, not group lessons—did not foster a sense of socialization in the child. Throughout his life, he maintained a few close friendships, with those who recognized his superiority at all times, and had no significant social or intellectual relationships except one, with the orchestra conductor Sergiu Celibidache. The birth of a younger brother in 1924, which provoked feelings of jealousy in him, and of a younger sister in 1926, who died at the age of seven, also played a significant role in shaping his personality.  (Piero Rattalino)