As he was about to die by a cursed ring, Dumbledore planned his own death with Severus Snape. Per the plan, Dumbledore was killed by Snape during the Battle of the Astronomy Tower. ... Dumbledore is the only Headmaster who was laid to rest at Hogwarts. A portrait of him still remains at Hogwarts.

Does Dumbledore really die in the Half Blood Prince?

So, did Dumbledore really die? The short answer is yes. The short answer to the question of who killed him and why, would be that Snape murdered him, being a traitor all along.

Why did Dumbledore allow himself to be killed?

Dumbledore knew he was dying because he had already found the Marvolo ring that brings back people from the dead, and like most mortals, he could not resist using it on himself. However, the curse of the ring was killing him slowly. ... Instead, Snape killed Dumbledore, meaning that Malfoy could basically remain innocent.