Gioacchino (sometimes known as Gioachino or Gioacchimo) Rossini was born on the 29 February, 1792 (a leap year), in the Papal States, Italy. His father was a trumpeter in various small bands and orchestras, and his mother a singer, so Rossini grew up knowing music and life in the theatre. He found it easy to sing and play music, and trained at the Conservatorio de Bologna although he was apparently rather lazy at his school studies. He composed his first opera, Demetrio e Polibio, when he was 14; it was staged six years later, in 1812.

Rossini is most famous for his operas, especially his comic ones. He composed operas mainly because it was the fashion of the time. His first comic opera was called La Cambiale di Matrimonio, which means in English The Bill of Marriage, and was reasonably successful in Venice. After a few more of his operas had been staged, he ended up with a contract with the committee of La Scala Opera House, Milan. La Scala is considered one of the best in Italy, if not in Europe. Under this contract he wrote La Pietra del Paragone, and several other operas, although not all were successes. He married a Spanish soprano, Isabella Colbran, who sang in several of his early operas.

Rossini was then offered a contract with a millionaire, Domenica Barbaia (owner of the two main theatres in Naples), who was impressed by Rossini's works. Rossini himself was impressed with the terms of the contract; he received security, and he only had to write two operas a year.

By 1816, Rossini had written ten more operas, most of which were successes, including L'Italiana in Algeri (The Italian Girl in Algiers, 1813) and Il Turco in Italia (The Turk in Italy, 1814). His 1816 opera, Il Barbiere di Siviglia (The Barber of Seville), was adapted from a popular play, and remains one of the most famous of all comic operas. The main character is called Figaro, and appears in another opera, a sequel to The Barber of Seville, although written before. It is called The Marriage of Figaro and was written by Mozart in 1786.

Rossini's last opera, written when he was 37, was Guillaume Tell (William Tell). The overture from this opera is still very popular, and essentially tells the whole story of the opera in music (which is the mark of a true overture). By this time, Rossini had enough money to last him for a while. He decided not to write for the theatre any more. He wrote various piano pieces, songs and religious music, but only the Stabat Mater (1842) was successful. As his parents were dead, he had no reason to stay in Italy, and went to live in Paris as a wealthy, wise nobleman, not working at all, but still one of the great personages of the musical world. He stayed there, with his second wife Olympe Pélissier, until his death in 1868.

Rossini was undoubtedly the most successful operatic composer of his time, and outstanding in his opera buffa; ('comic opera') with their light and lively music. He was particularly important for focussing on the bel canto ('beautiful song') style, which emphasises opera with beautiful melodies and opportunities for the singers to really show their abilities, rather than the later Wagnerian-style operas with their excesses of drama and emotion. He was Italy's last composer in this style.