Does Professor Slughorn die in the battle of hogwarts?

Answer 1

When the Dark Lord invaded the castle with his army, it was initially believed that Professor Slughorn had fled in cowardice; but as it transpired, had gone to Hogsmeade to round up reinforcements.

He returned to the castle at the head of vast number of residents and shopkeepers from the town, along with friends and family of the students and staff already fighting.

Slughorn engaged the Dark Lord head on, with McGonagall and Kingsley, proving himself a masterful duellist, able to hold his own against even the most dangerous dark wizard of all time.

Answer 2

Professor Lupin, though no longer a professor at the time was killed by Bellatrix Lestrange along with his Wife Nimphadora Tonks, and Professor Snape, also not a professor but the headmaster of Hogwarts in the seventh book. Snape was killed by He-Who-Must-Not-Be-Named, or Voldemort, under misunderstood supiction that Snape was the real holder of The Elder Wand.