What was Tchaikovsky most popular piece?

Tchaikovsky's most popular piece is widely considered to be "Swan Lake," a Ballet that premiered in 1877 and has become a staple of Classical Music and dance repertoire. Its lush melodies and emotional depth resonate with audiences, particularly the iconic "Dance of the Swans" and the tragic love story it portrays. Other notable works include the "1812 Overture" and "The Nutcracker," but "Swan Lake" remains his defining masterpiece.