Complex sentence: He was first sent to Shenkursk, in Archangel Governorate (now Archangelsk Oblast), in the Russia's north, arriving there in October 1887; in the summer 1890, he was transferred to Kola, on the Barents Sea.
Split into simpler sentences: He was first sent to Shenkursk, in Arkhangelsk Governorate (now Arkhangelsk Oblast), in the Russia's north, arriving there in October 1887. In the summer 1890, he was transferred to Kola, on the Barents Sea.