Arkhangelsk Oblast eventually spread well beyond the Arkhangelsk Region. The Mezen horses, bred in the Mezen River valley, are rather small but suitable for difficult work and easily survive cold winters. The area of current Arkhangelsk Oblast has always been located on the trading routes connecting central Russia to the White Sea, and, in fact, in the 17th century the White Sea was the main sea export route for Russia. The whole course of the Northern Dvina is navigable, as well as the lower course of some of its tributaries, most notably the Vychegda, the Vaga, and the Pinega. The Mezen is
Port of Murmansk Arkhangelsk and St. Petersburg (later renamed Petrograd). However, after the blocking of the Ottoman Empire's straits of the Bosphorus and Dardanelles to outside shipping and blockading of the Baltic Sea port of St. Petersburg, the Russian Empire could only use the northern port of Arkhangelsk. This port had limitations: when winter presented itself, navigation and shipping of any sort came to a halt. Therefore, it was decided to build a new port. The chosen location was in Murmansk due to its ability to accommodate sea traffic year-round, proximity to existing communities and relative ease to connect it to the empire's