Brandenburg Concerto No. 5 "Brandenburg Concertos" takes a central place. Nonetheless around half a dozen of Bach's extant concertos, including some of the "Brandenburg Concertos" and lost models of his later harpsichord concertos, seem to have had their roots in his Weimar period. Most of what Bach may have left with his employer in Weimar perished in a fire destroying Schloss Weimar in the 1770s. In 1719 a new large two-manual harpsichord arrived in the residence of Bach's then-time employer at Köthen. BWV 1050a, an extant early version of the fifth "Brandenburg Concerto", may have been conceived for this instrument, but that seems unlikely
Brandenburg-Prussia after the victory at Fehrbellin and the Brandenburg-Prussian advance in Swedish Pomerania during the Scanian War, Frederick William decided to establish a navy. He engaged Dutch merchant and shipowner Benjamin Raule as his advisor, who after a first personal meeting with Frederick William in 1675 settled in Brandenburg in 1676 and became the major figure of Brandenburg-Prussia's emerging naval and colonial enterprise. The Brandenburg-Prussian navy was established from ten ships which Frederick William leased from Raule, and achieved first successes in the war against Sweden supporting the siege of Stralsund and Stettin and the invasion of Rügen. In Pillau (now