But the period of Bach's activity in the line of chamber music properly began after he left Weimar in response to an invitation to become capellmeister at the court of Prince Leopold of Anhalt-Cöthen. It was probably on account of his not having been appointed to the same office in Weimar, after the death of the venerable Samuel Drese, a preferment which he had every reason to expect, that he gave up his post as organist in the town. The love and protection always bestowed by the duke upon old and trusty servants prevailed in this instance over his interest in art, for he allowed Drese's very incompetent son to succeed his father. The Prince of Cöthen was allied to the ducal family of Weimar through the marriage of his sister to the heir apparent of the reigning house, and on the occasion of his visit at the time of the wedding festivities, it is very likely that Bach may have attracted his attention. He was just the man to appreciate the importance of so great a musician. Clear-sighted and enthusiastic, unmarried and still in the spring-time of life, he was endowed with an unbiased judgment and the ability to rule, as well as with an unusual talent for music. He played several instruments, was an excellent bass singer, and Bach said of him in after years that he not only loved music but understood it. And it was precisely chamber music that was almost exclusively cultivated in Cöthen. The province professed the Calvinistic faith and music therefore played an entirely subordinate rôle in ecclesiastical and social life. Bach had no official connection with the church organs in the place. The court never possessed an opera and seems to have been only sparingly provided with singers. Bach's labors were therefore limited to the concerts held at the castle, in which the prince himself took part, and which were especially signalized by the musician's own appearance as performer and composer. There was in Cöthen no opportunity for stepping before the public, and it testifies to the genuineness of Bach's nature and his devotion to instrumental art that he could spend with enjoyment six of the best years of his life in this position, so devoid of all external attraction. During this time he wrote the greater part of his chamber works, including the first part of the "Wohltemperirte Clavier," the "Inventionen und Sinfonien," the sonatas and suites for violin and violoncello without accompaniment, and also with the clavier; finally, the six great concertos dedicated to Margrave Christian of Brandenburg. The prince manifested the warmest attachment for Bach, treated him as a friend in every way, and at last could so little dispense with his society that the two undertook frequent journeys together, in the course of which they twice made a prolonged stay at Carlsbad. Bach meantime did not relinquish his independent professional tours and was often summoned in different directions for the inspection of organs.