Final answer:
Genghis Khan is being referred to as 'he' in the given statement. He is known for leading large armies of foreign mercenaries and uniting people into the Mongol Empire.
Step-by-step explanation:
The given statement, 'he is at this time transporting large armies of foreign,' is referring to Genghis Khan. Genghis Khan, also known as Chinggis Khan, was the leader who united a million or so people into the Mongol Empire, altering the trajectory of their lives and laying the foundations for the modern world to emerge. He led large armies of foreign mercenaries to conquer various lands.