After leaving Hogwarts in
1945, Riddle surprised everyone by working at a dark magic shop named Borgin and Burkes on Knockturn
Alley. His job there was to ferret out items of value and obtain them at the
lowest price possible. He was very good at this, but he abruptly left this job
and disappeared after he killed Hepzibah Smith for a gold locket that
belonged to Slytherin, and the gold cup that belonged to Helga Hufflepuff.

Riddle disappeared for
over ten years. During this time he "traveled far and wide ... sank so
deeply into the Dark Arts," "consorted with the very worst"
witches and wizards, and "underwent so many dangerous, magical
transformations" in his quest for power and immortality. When he returned
he was known as “Lord Voldemort.”

By the early 1970s,
Voldemort had a growing legion of thuggish followers he called “Death Eaters,”
and he was so fearsome that few dared speak his name. Few people realized he
was the same handsome and brilliant boy who had been so accomplished and well
liked at Hogwarts. In addition to his Death Eaters, Voldemort formed alliances
with dark creatures such as werewolves and dementors; he also controlled armies
of Inferi (animated corpses).

Many of the witches and
wizards who joined him came for a share of the power he offered, but
increasingly many joined his following out of fear of reprisal. "The years
of Voldemort's ascent to power were marked with disappearances," and
increasingly open violence.

Each Death Eater bore a
sign, the Dark Mark, a skull with a serpent protruding from its mouth like
a tongue, burned into his or her left inner forearm by the "Dark
Lord"; when they had killed, Death Eaters would send the same sign into
the air, comprised of emerald stars blazing in a haze of greenish smoke,
causing terror when it was seen.

Voldemort’s first reign
of terror lasted eleven years. During this time, Voldemort and his minions
attacked anyone who resisted or who defended the rights of Muggles and
Muggle-born wizards, and marked the gruesome scenes of torture and murder with
the Dark Mark lest anyone else think to stand in their way. Whole families were
wiped out and many others went into hiding.

Overwhelmed by reports of
deaths, disappearances, and torture in an atmosphere of terror, Bartemius
Crouch, then Head of the Department of Magical Law Enforcement, authorized
Aurors to use the Unforgivable Curses against suspects, empowered them to kill
rather than capture, and some suspects were handed to the dementors without
trial. Still, the Ministry could not cope with the situation, so Albus
Dumbledore began organizing the resistance, creating the group that became
known as The Order of the Phoenix.

The Order was frightfully
outnumbered, however, and the Death Eaters were killing the members of the
Order off, many times killing their entire families along with them. Lord
Voldemort seemed “mightier than any wizard living," and had achieved his
goal; most of the wizarding world avoided saying his name, when they spoke of
him at all they referred to him as You-Know-Who, or He-Who-Must-Not-Be-Named.

At the height of his
power in the late 1970s, Voldemort was to recruit two young Death Eaters who
would turn on him in different ways. Severus Snape and Regulus Black joined
the Death Eaters for different reasons, but both of them came to realize that
they could not support Voldemort’s methods or stand by when he hurt the ones
they loved. Regulus, furious about Voldemort’s abuse of Kreacher, was to
die trying to sabotage one of Voldemort’s Horcruxes, and Snape became a
double agent for Dumbledore after Voldemort decided to attack Lily Potter.
Ironically, Snape was the one who told Voldemort of the prophecy he overheard
identifying a child who would have the power to vanquish the Dark Lord. Snape
was horrified when Voldemort decided that the Potter’s child Harry was the
child of the prophecy. Voldemort learned only part of the prophecy: that this
person would be born at the end of July to parents who had survived three
attempts to kill them. Voldemort realized that he must find and kill that child.

Dumbledore would not need
Snape’s skills for many years to come; Voldemort’s physical body was destroyed
when the Avada Kedavra curse he aimed at one-year-old Harry Potter rebounded
on him. His mother Lily’s self-sacrifice seconds before had unexpectedly
protected her son. Voldemort’s Horcruxes worked, but for nearly a
decade he could only live by possessing the bodies of others. Many of his Death
Eater followers were tried by the Wizengamot and sentenced to Azkaban.

After Voldemort fled, he
hid in a forest in Albania, far from humans and from the Aurors he knew would
still be searching for him, using the only power left to him, the ability to
possess the bodies of others, he inhabited animals, snakes being his
preference.

He waited, sleeplessly,
forcing himself to exist second by second, expecting his faithful Death Eaters
to try to find him and perform the magic that would restore him, but those
Death Eaters who were not killed by Aurors or imprisoned in Azkaban were
denying they had ever been involved with Voldemort or claiming they had been
cursed and forced to kill and torture against their will.