Plot to bring back Lord Voldemort

Plot to steal the Philosophers Stone

This was Voldemort's first notable attempt at regaining power. Once he subjugated him, he ordered then- Defense against the Dark Arts professor a Hogwarts, Quirinus Quirrell, to steal the Philosopher's Stone from Gringotts.

After his failure, Voldemort kept a closer eye on him by possesing him. He then plotted (with Quirrell's help) to steal it at Hogwarts.

Later in the school year, Quirrell (on Voldemort's orders) sent a fake letter to Dumbledore, telling him to go to the Ministry. Once past the enchantments, however, Quirrell could not get the stone. A few minutes later, Harry Potter arrived, and Quirrell used him to try and get the stone. After Harry lied, Voldemort attempted to kill Harry himself, but for the same reason as he failed last time, he failed again.

Triwizard Tournament

During the 1994-1995 school year Voldemort, knowing the Triwizard Tournament was going on at Hogwarts formed a plant to return to full power. He sent Barty Crouch Jr. and Wormtail, to overpower the famous and paranoid ex-auror Alastor "Mad Eye" Moody, who would be the D.A.D.A professor at Hogwarts. They sucessfully overpowered him, and through the guise, Barty Crouch Jr. made sure Harry Potter would compete in the tournament, guided him so that he would be the first one to touch the Triwizard Cup, which he turned into a portkey to transport him (and inadvertently Cedric Diggory) to Lord Voldemort. Once there, Wormtail killed Cedric, took Harry's blood and formed the potion that would revive Lord Voldemort.

However, Moody snagged Harry when he got back (something the real Moody would never have done) causing Dumbledore, Snape , and McGonagall to rush to Harry 's aid.

After exposing his identity and intentions, Barty Crouch Jr. was sentenced to thee Dementor's Kiss.