Gellert Grindelwald and Albus Dumbledore shared a complex relationship. They first met when Dumbledore was seventeen, introduced by Grindelwald's great aunt, Bathilda Bagshot. They quickly became friends, sharing common interests such as the quest for the Deathly Hallows and ideas about a wizard-led society. Their relationship eventually evolved beyond friendship, with Dumbledore falling in love with Grindelwald. This love blinded Dumbledore to Grindelwald's harmful anti-Muggle views and led them to make a blood pact, preventing them from fighting each other. However, Grindelwald revealed himself to be a Dark wizard, causing a rift between them. Despite this, Grindelwald still considered Dumbledore a friend to some extent.