Known for centuries as a set of insignificant cliffs surrounded by a number of treacherous sunken rocks, Str�msborg is represented on Petrus Till�us' 1733 map as uninhabited and named Stensk�r ("Stone Skerry"). This name has survived as the original name of the present island. However, it is far from certain that this ever was a proper name in common use. For example, in 1747 Till�us mentions it as det stensk�r eller klippa som �r bel�get uti Norra Str�m och Melaren ("the stone skerry or cliff that is located in Northern Stream and M�laren") and says it occupied an area of 2.944 square ells (kv.alnar) in size. In a letter in 1647 Queen Christina donates the island to her half-brother referring to it as den lille holmen eller sk�ret ("the small islet or skerry"). Most likely the cliffs didn't have an official name at the time and as they certainly didn't appear in city planning records, the queen's donation of these insignificant cliffs to her half-brother arguably was a carefully studied insult. They did, nevertheless, remain unexplored during her era, and it is possible the skerry shared the fate of many other structures at this time, and had a popular name "not suitable for print". Of the approximately 35 maps of Stockholm produced during the 17th century only one includes Str�msborg but provides very little information.
The merchant Berge Olofson Str�m bought the island in 1740, and, according to a description from 1896 (G. Nordensvan), ten years later he had a stone house ("suitable in size") surrounded by lime trees built on the island. Whenever the small island received its present name, it must have been in reference both to Str�mmen ("The Stream"), the stream surrounding it, and to the merchant "Str�m" and his building with the appearance of a castle (Str�ms-borg, "Stream's Castle"). Further, Nordensvan tells the island has been the site for several restaurants, skittle alleys, and public baths, and "...was a small idyllic spot, particularly at that
