Anhalt-Köthen in the context of Joachim Ernest, Prince of Anhalt

Johann Sebastian Bach (31 March [O.S. 21 March] 1685 – 28 July 1750) was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the cello suites and sonatas and partitas for solo violin; keyboard works such as the Goldberg Variations and The Well-Tempered Clavier; organ works such as the Schübler Chorales and the Toccata and Fugue in D minor; and choral works such as the St Matthew Passion and the Mass in B minor. Since the 19th-century Bach Revival, he has been widely regarded as one of the greatest composers in the history of Western music.

The Bach family had already produced several composers when Johann Sebastian was born as the last child of a city musician, Johann Ambrosius, in Eisenach. After being orphaned at age 10, he lived for five years with his eldest brother, Johann Christoph, then continued his musical education in Lüneburg. In 1703 he returned to Thuringia, working as a musician for Protestant churches in Arnstadt and Mühlhausen. Around that time he also visited for longer periods the courts in Weimar, where he expanded his organ repertory, and the reformed court at Köthen, where he was mostly engaged with chamber music. By 1723 he was hired as Thomaskantor (cantor with related duties at St Thomas School) in Leipzig. There he composed music for the principal Lutheran churches of the city and Leipzig University's student ensemble, Collegium Musicum. In 1726 he began publishing his organ and other keyboard music. In Leipzig, as had happened during some of his earlier positions, he had difficult relations with his employer. This situation was somewhat remedied when his sovereign, Augustus III of Poland, granted him the title of court composer of the Elector of Saxony in 1736. In the last decades of his life, Bach reworked and extended many of his earlier compositions. He died due to complications following eye surgery in 1750 at the age of 65. Four of his twenty children, Wilhelm Friedemann, Carl Philipp Emanuel, Johann Christoph Friedrich, and Johann Christian, became composers.

The House of Ascania is an Old Saxon high noble family historically documented since the 11th century. It is also known as the House of Anhalt, which refers to its longest-held possession. Their ancestral seats, Ballenstedt, Anhalt, Aschersleben, and Bernburg, are located in the present-day Anhalt region in Saxony-Anhalt. The ruins of Anhalt Castle are situated in the Harz Mountains northeast of Harzgerode. The name "Askanier" derives from the Latinization of their seat at Aschersleben. Since the late 17th century, only the Anhalt branch has survived. Albert the Bear became Duke of Saxony in 1138 and, with the control of the Margraviate of Brandenburg in 1150, the first Margrave in the formerly Slavic settlement area. In 1180, eastern parts of the Stem Duchy of Saxony passed to the Askanier Bernhard of Saxony. As Dukes of Saxe-Wittenberg, the family received hereditary electoral dignity in 1356. The family ruled Anhalt-Dessau, Anhalt-Bernburg, Anhalt-Köthen, Anhalt-Zerbst, Anhalt-Plötzkau, and Anhalt-Aschersleben. Alexius Friedrich Christian of Anhalt-Bernburg was the first of the Anhalt princes to gain the title of Duke in April 1806. The ducal title was adopted in Anhalt-Köthen and Anhalt-Dessau in 1807. Since 1863, only the Dessau line has existed, with Aribert of Anhalt abdicating in 1918 due to the November Revolution in the Duchy of Anhalt. Since 1963, Eduard, Prince of Anhalt has been the head of the family.

The Principality of Anhalt (German: Fürstentum Anhalt) was a State of the Holy Roman Empire, located in Central Germany, in what is today part of the federal state of Saxony-Anhalt.

Under the rule of the House of Ascania, the Anhalt territory was split off the German stem duchy of Saxony in 1212 and granted to Count Henry I, who was raised to the rank of a Prince of the Holy Roman Empire in 1218. Ruled by Ascanian princes from the High Middle Ages to the Early modern period, Anhalt was divided several times amongst various lines of the dynasty until the dissolution of the Empire in 1806, when Napoleon elevated the remaining states of Anhalt-Bernburg, Anhalt-Dessau and Anhalt-Köthen to duchies.

Anhalt-Zerbst was a principality of the Holy Roman Empire ruled by the House of Ascania, with its residence at Zerbst in present-day Saxony-Anhalt. It emerged as a subdivision of the Principality of Anhalt from 1252 until 1396, when it was divided into the principalities of Anhalt-Dessau and Anhalt-Köthen. Recreated in 1544, Anhalt-Zerbst finally was partitioned between Anhalt-Dessau, Anhalt-Köthen, and Anhalt-Bernburg in 1796 upon the extinction of the line.

Henry of Anhalt-Köthen (30 July 1778 – 23 November 1847) was a German prince of the House of Ascania, ruler of the non-sovereign principality of Anhalt-Pless and the last ruler of the duchy of Anhalt-Köthen.

Leopold of Anhalt-Köthen (29 November 1694 – 19 November 1728) was a German prince of the House of Ascania and ruler of the principality of Anhalt-Köthen. Today, he is best remembered for employing Johann Sebastian Bach as his Kapellmeister between 1717 and 1723.

He was born at Köthen, the second (but eldest surviving) son of Emmanuel Lebrecht, Prince of Anhalt-Köthen, by his wife Gisela Agnes of Rath.