Southwest Pamir, the most southern massif of the Pamir mountains located in the territory of Tajikistan, to be exact the mountain of Badakhshansky autonomous region. From the North the area is limited to the Rushansky ridge with the main top peak Patkhor (6080 m). Further in the south range of Shokhdara stretches. In which near the plateau located in the place of merge of the river Vakhandarya and the river Pandzh which is boundary with Afghanistan the dominating area tops, Marx's peaks (6723 m) and Engels (6510 m) are located. In 1895 on Russian-English differentiation Badakhshan was divided: the territory on the left coast Pyandzh departed to Afghanistan, right-bank Badakhshan was passed Bukhara, from Russia. The part of the uniform Pamir population in the ethnic relation living for Pyandzh appeared abroad. Two highest tops of the area on the Russian coast Pyandzh received the names King (nowadays Marx's peak) and the Queen (nowadays Engels peak).
The first climbing expedition under the leadership of E. A. Beletsko worked at South west Pamir in 1946 investigation of the Rushansky ridge around the item Patkhor Was carried out, and ascension on peak is made. After a successful completion of investigation, in the second half of August the caravan of an expedition crossed the Shugnansky ridge through the pass Duzakh-dara, and on the valley of the river Redzhig approached Karl Marx's peak. Two prospecting groups went to the bottom of peak on valleys of the rivers Shabay and Hatsak then the way of ascension from a glacier Hatsak, through the pass Nishgar on Marx's plateau, and further on the western crest was chosen. The top was reached on September 6, 1946, at 13:30, in difficult weather conditions. After ascension E. A. Beletsky rose by the pass in east part of the Shakhdarinsky ridge, to the east of the item of Engels, (Pogranichnikov Lane). 1954: a pervovoskhozhdeniye on Engels peak of 6510 m, a route on a direction of the southern wall.