An important expedition in this process was funded by the (*) Stroganov family and led to the fall of Qashliq to Yermak Timofeyevich after the Battle of Chuvash Cape.
Descriptive answer acceptableAn early leader of this process apocryphally died while trying to cross a river because the armor given to him by his ruler was too heavy. One battle in this process saw the general Mametqul fail to use his cannons and the flight of Khan Kuchum to Bukhara. This process allowed for the katorga system and was consolidated by the construction of ostrogs at river confluences and portages, which aided the collection of yasak. An important expedition in this process was funded by the (*) Stroganov family and led to the fall of Qashliq to Yermak Timofeyevich after the Battle of Chuvash Cape. The spread of smallpox that accompanied this process devastated peoples like the Yukagir, Tungus, and Yakuts. For 10 points, what was this process that extended the borders of Russia to the Pacific Ocean?
Descriptive answer acceptableAn early leader of this process apocryphally died while trying to cross a river because the armor given to him by his ruler was too heavy.
Russian conquest of Siberia (accept logical equivalents)