Köping (historically) was an important Viking Age port of what is today's Sweden, covering an area of approximately 25 hectars, almost 4 times larger than the similar site on the island of Björkö near Stockholm. Köping was in operation from the 7th to the 13th century. It was also an important center of early Christianity in Sweden. Remains of an unfinished, massive 12th century church 42 meters long have been excavated as well as the largest collection of the so-called eskilstunakistor, 75 pieces. During the last ten years there have been several small excavations which have confirmed the earlier findings and the importance of the site. Note that these findings are almost unknown to public in Sweden and the ruling view is that little site on Björkö is Sweden's "oldest town".
Köping faded away around 1200, and Kalmar took over as the most important harbour town in south-eastern Sweden.
Köping is claimed by some amateur historians and historians as a possible alternative to Björkö for the location of the old viking village Birka in SvíÞjóð (the ancient name for Sweden). Birka is mentioned in Vita Ansgari and the work of Adam of Bremen. He states that Birka is situated directly north of Jomsborg and directly opposite to Kurland and at the same distance between them. This theory has not been widely accepted.