albus dumbledore is a headmaster for a school of magic
towards the end of the book dumbledore explains to harry that voldemort chose him as his equal and that one must kill the other in the end and confesses that his great affection for harry has clouded his judgement
 dumbledore and grindelwald suggest that they have to leave the dumbledore home to carry on their plans but aberforth protested against this as arianas condition would not allow her to be moved