Snape at Hogwarts

Years: 1971 to 1978.

House: Slytherin (JKR).

Career:

Potions Master and Head of Slytherin House since 1980, appointed Teacher of Defense Against the Dark Arts in 1996, Headmaster of Hogwarts between 1997 and 1998. During the first six books, Snape is a teacher hated by all, except the students from his house. Some even fear him, like Neville Longbottom (whose boggart becomes Snape), and his character is often described as nasty, sarcastic and even cruel.

Office:

Adjacent to the Potions classroom in the dungeons.

Potions Classroom:

A cold and dark place, the walls were lined with glass jars with slimy bits of some dead animal and plants.

Defence against the Dark Arts classroom:

He made it dark and gloomy with pictures of people "in pain, sporting grisly injuries or strangely contorted body parts."

Headmaster's Office:

He did not change it much, or at least Harry didn´t notice it.

Some descriptions from the books:

"Snape always been fascinated by the Dark Arts, and was famous for it at school" Sirius Black
"Snape knew more curses when he arrived at school than half the seventh-grade boys, and belonged to the group of Slytherins who later became Death Eaters" Sirius Black