These six suites for harpsichord are the last set that Bach composed and the most technically demanding of the three. They were composed between 1725 and 1730 or 1731. As with the French and English Suites, the autograph manuscript of the Partitas is no longer extant.
In keeping with a nineteenth-century naming tradition that labelled Bach's first set of Suites English and the second French, the Partitas are sometimes referred to as the German Suites. This title, however, is a publishing convenience; there is nothing particularly German about the Partitas. In comparison with the two earlier sets of suites, the Partitas are by far the most free-ranging in terms of structure. Unlike the English Suites, for example, each of which opens with a strict Prelude, the Partitas feature a number of different opening styles including an ornamental Overture and a Toccata.
Although each of the Partitas was published separately, they were collected into a single volume (1731), known as the Clavier-Übung I (Keyboard Practice), which Bach himself chose to label his Opus 1. Unlike the earlier sets of suites, Bach originally intended to publish seven Partitas, advertising in the Spring of 1730 upon the publication of the fifth Partita that the promised collected volume would contain two more such pieces. This intention is further signalled by the spread of keys, which follows a clear structure, B-Flat - c, a - D, G - e, leaving F as the logical conclusion. The Italian Concerto, which is in the key of F and was published in the Clavier-Übung II, likely originated therefore as one of the Partitas before expanding beyond the dictates of the Suite form.