Arriving in Irkutsk, they soon found the area unsuitable; Stallybrass visited various places before setting up a mission station in Selenginsk (modern-day Novoselenginsk) in 1819, among the Buryat people; he was joined by two Scotsmen, William Swan (born 1791) and Robert Yuille (born 1786).
In 1688, the ostrog was besieged by the Khalkha Mongols for two months, but they had to withdraw when their main territory was attacked by the Western Mongols.