Certainly a great Russian Romantic Period composer with piano (3 Piano Concertos), violin (1 Violin Concerto), 6 symphonies, 4 orchestral suites and ballets (1. Nutcracker, 2. Swan Lake, 3. Sleeping Beauty). His famous operas were: Eugene Onegin by Alexander Pushkin and Queen of Spades.
Also one whom many like to label as homosexual without much concrete evidence: All they have were his depression, failed marriage (with Antonina Miliukova, his student, threatening suicide for his love) and how Russian was against LGBTQ+. His letters to his brother, Modest, about how beautiful (angelic, tempting delightful young creature, attractive bait, stunning beauty, etc.) some men were. None of these are enough to prove anything. They would probably call King David gay for his relationship with Jonathan, son of King Saul.
Starting piano lessons at 5. Went into law school (Imperial School of Jurisprudence in St. Petersburg) because of parents. Peter studied under Anton Rubinstein in St. Petersburg Conservatory.
Married Antonina Miliukova in 1877, who was 9 years younger than he. Never divorced but lots of drama. 14 years financed by wealthy, older widow, Nadezhda von Meck whom he never met in person as she insisted to keep relationship strictly through letters.
Died Nov 6 1893 in St. Petersburg.
Source of this summary from Classical Archives.