Apparently, climbs of Damavand were not uncommon during the early 13th century, before the Mongol invasion under Hulagu Khan swept, and destroyed, everything before it.Actually, at the time of Thompson's ascent in 1837, there were ascents regularly being made by Iranians, to gather sulphur from the summit for commercial purposes; Thompson himself mentions this in his article in the Royal Geographic society magazine of 1838. This commercial activity was mentioned in Nasser-i Khosrow's medieval book of travels.
