Here you can find bitz and parts out of the Warhammer 40k Space Marine Commander box.
In Space Marine chapters, which are loyal to the Codex Astartes, each company is under the command of a captain. These veterans have the command over their brothers. They are experienced tacticians and hardened fighters who seek their sort. Space Marine Company Captains are subject only to the Chapter Master, the supreme commander. He is the leader of the Chapter, and it is in his hands to bear the law and the will of the Emperor to every corner of the Warhammer 40,000 galaxy. His bravery is outstanding and his skills are truly legendary. He alone decides on the actions of the Chapter, and he is only accountable to the Emperor himself.