Complex sentence: After the transfer in 1905 of South Sakhalin to the Japanese world of Portsmouth in 1904, remaining a full orphan Basil was sent to study in Japan, where in September 1907 he studied at the Theological seminar in Tokyo.
Split into simpler sentences: After the transfer in 1905 of South Sakhalin to the Japan under the Treaty of Portsmouth in 1904, Vasili by this time an orphan was sent to study in Japan. Starting in September 1907 he studied at the Theological seminar in Tokyo.