"And let it be known that Slytherin House played its part! Let our contribution not be forgotten!" — Phineas Nigellus, following the Battle of Hogwarts and Voldemort's death (Deathly Hallows - Page 747 US Hardcover)
I know that this answer says that "Phineas was talking about Snape". I disagreed with this answer. The accepted answer of this question is saying that Slytherins were reinforcements led by Slughorn. Now forgive me, I doubt these two answers. Nevertheless, who was Phineas Nigellus Black talking about? Was it Snape, Slughorn or the Slytherins who were reinforcements?