brienneoftvrth:
During the 1997-1998 school year, Snape was named Headmaster of Hogwarts, while Death Eaters Alecto and Amycus Carrow were appointed Deputy Heads. Snape used his position as Headmaster to discreetly protect the students and to contain the Carrows. It is later understood that, during his time as Headmaster, Snape consulted with the portraits of the previous headmasters, and continued to receive instructions from Dumbledore’s portrait.