Ludwig van Beethoven, (December 16, 1770  – March 26, 1827) was a German pianist, virtuoso and composer. He was an important figure in the transitional period between the Classical and Romantic eras in Western classical music, and remains one of the most famous and influential composers of all time.

Born in Bonn, Germany, he moved to Vienna, Austria, in his early twenties and settled there, studying with Joseph Haydn and quickly gaining a reputation as a virtuoso pianist. Beethoven's hearing gradually deteriorated beginning in his twenties, yet he continued to compose masterpieces, and to conduct and perform, even after he was completely deaf.

Beethoven's parents were Johann van Beethoven (1740 in Bonn –1792) and Maria Magdalena Keverich (1744 in Ehrenbreitstein–1787). Magdalena's father Johann Heinrich Keverich had been Chef at the court of the Archbishopric of Trier at Festung Ehrenbreitstein fortress opposite to Koblenz. Beethoven was, like their first child Ludwig Maria, named after his father's father Lodewijk van Beethoven (1712–1773), a musician of Roman Catholic Flemish ancestry who was at one time Kapellmeister at the court of Clemens August of Bavaria, the Prince-Archbishop-Elector of Cologne, and who married Beethoven's grandmother Maria Josepha Ball (1714–1775) in 1733.

Beethoven was born in Bonn, Germany in 1770. Of the seven children born to Johann Beethoven, himself the only survivor of three, only second-born Ludwig and two younger brothers survived infancy. Beethoven was baptized on December 17, 1770. Although his birth date is not known for certain, his family celebrated his birthday on December 16.

In 1787, the young Beethoven travelled to Vienna for the first time, in hopes of studying with Wolfgang Amadeus Mozart. It is not clear whether he succeeded in meeting Mozart, or if he did whether Mozart was willing to accept him as a pupil. In any event, the declining health of Beethoven's mother, dying of tuberculosis, forced him to return home after only about two weeks in Vienna. Beethoven's mother died on July 17, 1787, when Beethoven was 16.

In 1792, Beethoven moved to Vienna, where he studied for a time with Joseph Haydn: his hopes of studying with Mozart had been shattered by Mozart's death the previous year. Beethoven received additional instruction from Johann Georg Albrechtsberger (Vienna's pre-eminent counterpoint instructor) and Antonio Salieri. By 1793, Beethoven established a reputation in Vienna as a piano virtuoso. His first works with opus numbers, a set of three piano trios, appeared in 1795. He settled into the career pattern he would follow for the remainder of his life: rather than working for the church or a noble court (as most composers before him had done), he supported himself through a combination of annual stipends or single gifts from members of the aristocracy; income from subscription concerts, concerts, and lessons; and proceeds from sales of his works.

Beethoven’s patrons loved his music but were not quick to support him. He eventually came to rely more on patrons such as Count Franz Joseph Kinsky, (d. 1811), Prince Joseph Franz Maximilian Lobkowitz (1772-1816) and Karl Alois Johann-Nepomuk Vinzenz, Fürst Lichnowsky, and as these patrons passed away or reneged on their pledges, Beethoven fell into debt. In 1807, Prince Lobkowitz advised Beethoven to apply for the position of composer of the Imperial Theatres, but the nobility who had newly been placed in charge of the post did not respond. Beethoven considered leaving Vienna: in the fall of 1808, he was offered a position as chapel maestro at the court of Jerome Bonaparte, the king of Westphalia, which he accepted. To persuade him to stay in Vienna, the Archduke Rudolf, Count Kinsky and Prince Lobkowitz, after receiving representations from the composer’s friends, pledged to pay Beethoven a pension of 4000 florins a year. Only Archduke Rudolf paid his share of the pension on the agreed date. Kinsky, immediately called to duty as an officer, did not contribute and soon died after falling from his horse. Lobkowitz stopped paying in September 1811. No successors came forward to continue the patronage, and Beethoven relied mostly on selling composition rights and a smaller pension after 1815.

He was one of the first composers to systematically and consistently use interlocking thematic devices, or germ-motives, to achieve inter-movement unity in long compositions. Equally remarkable was his use of source-motives, which recurred in many different compositions. He made innovations in almost every form of music he touched. For example, he diversified even the well-crystallized form of the rondo, making it more elastic and spacious, and also bringing it closer to sonata form.

Beethoven composed in various genres, including nine symphonies, five piano concertos, thrity two piano sonatas, other sonatas (including for violin), string quartets and other chamber music, masses, an opera, and Lieder. He is viewed as one of the most important transitional figures between the Classical and Romantic eras of musical history.

Beethoven adopted the principles of sonata form and motivic development that he inherited from Haydn and Mozart, and he greatly extended them, writing longer and more ambitious movements.

Beethoven's compositional career is usually divided into Early, Middle, and Late periods. In this scheme, his early period is taken to last until about 1802, the middle period from about 1803 to about 1814, and the late period from about 1815.

In his Early period, he is seen as emulating his great predecessors Haydn and Mozart, while exploring new directions and gradually expanding the scope and ambition of his work. Some important pieces from the Early period are the 1st and 2nd symphonies, the first six string quartets, the first three piano concertos, and the first twenty piano sonatas, including the famous Pathétique and Moonlight sonatas.

His Middle period began shortly after Beethoven's personal crisis brought on by his recognition of encroaching deafness. It is noted for large-scale works that express heroism and struggle, many of which have become very famous. Middle-period works include six symphonies (Nos. 3–8), the 4th and 5th piano concertos, the strangely unsatisfactory Triple Concerto and the single Violin Concerto, five string quartets (Nos. 7–11), the next seven piano sonatas (including the Waldstein and the Appassionata), the Kreutzer Violin Sonata and Beethoven's only opera, Fidelio.

Beethoven's Late period began around 1815. Works from this period are characterized by their intellectual depth, their formal innovations, and their intense, highly personal expression. For example, the String Quartet, Op. 131 has seven linked movements, and the 9th Symphony adds choral forces to the orchestra in the last movement. Other compositions from this period include the Missa Solemnis, the last five string quartets (including the massive Grosse Fuge) and the last five piano sonatas, of which the Hammerklavier Sonata, Op. 106, is the best known.