Since graduating from Hogwarts, Russell has been trying to apply for a teaching position in his alma mater.

Unlike other wizards who used to be law-abiding and cautious, Russell chose to go all the way and directly apply to replace Dumbledore as the headmaster.

After three consecutive years of failed applications, in 1992, when Hogwarts was facing a basilisk crisis, he decisively seized the opportunity.

PS1: First became the headmaster, then the dean of studies.

PS2: Timeline trio second grade.