Early Life Doctor Victor von Doom is a brilliant scientist and supreme ruler of the European country Latveria, and considered as the most dangerous criminal by S.H.I.E.L.D.. Being the leader of a sovereign he has diplomatic immunity meaning he can not be arrested while on foreign soil.
Doomed To prove themselves, the S.H.I.E.L.D. trainees led by Spider-Man went to Latveria and tried to capture Doom. His easy defeat was really a trap, being a Doombot the Doctor Doom the heroes brought to S.H.I.E.L.D.
While fighting one Doombot damages one of the engines, making the helicarrier loose stability. The main Doombot attacked the nuclear reactor of the Helicarrier. Spider-Man convinced Nova to use his powers to lift the Helicarrier, while the other three takes care of the Doombots. Finally, when they arrive to the reactor, the team worked together and destroyed the Doombot. The Doctor Doom contacted the team himself threatening the them.
Not a Toy When Spider-Man accidentally looses Captain America's Shield it lands in of all in the Latverian Embassy, in New York City where it is found by Doctor Doom. Spider-Man is met by Captain America who decide to try and sneak into the embassy and retrieve the shield before Doctor Doom has a chance to exploit it for his own nefarious purposes. They have to fight pass lasers and a horde of Doombots, even a pack of Doom Dogs. While in the Embassy they learn that Doom had plans to attack various targets across the United States. Cap using Doom's computers deactivates the Doombots and go after Doom who is escaping in a craft on the roof. They are attacked by another pack of Doom Dogs and missiles. After a short battle they web on to Dooms craft and smash through the screen, but Cap is hit by his own shield. They land in Central Park and blast the two heroes but they dodge his attack. No longer on Latverian soil he is forced to return the Shield as S.H.I.E.L.D. agent escort him away.
The Avengers Protocol Red Skull defeated decides it's time to create a Cabal of villains to help him defeat the The Avengers. He send out probes to recruit Doctor Doom, the Atlantean barbarian Attuma and Dracula the king of the Vampires.
Ultimate Deadpool Deadpool's told the S.H.I.E.L.D. trainees and Spider-Man of the time he defeated Doctor Doom and half his army single-handedly and then made a puppet of him with a mustache, but due to his fractured mind it is impossible to tell if this story is true. 
The Serpent of Doom Doom recovers the Rock Troll Ulik's weapon Codgel after a fight with the Avengers. The team track the weapons energy signature to the Latverian Embassy and battle Doom and his Doombots. Doom with a little modification uses the weapon to release the Midgard Serpent with hopes of using it to conquer the globe. The creature is to powerful and would continue to grow until it consumes the Earth. After a battle with the Avengers he and the creature are banished to the Realm Below using the extra-dimensional portal used by Ulik. 
Doomstroyer Doctor Doom takes control of the Destroyer Armor where he drives away the Hydra Agents and the A.I.M. Agents. The Destroyer then attacks the Avengers. With help from Loki, Thor, Captain America, and Falcon were able to track Doctor Doom to Helheim where he is using the Helhorn to control the Destroyer. Iron Man then gets through to Doctor Doom and convinces him to deactivate the Destroyer. When Loki tries to take control of the Destroyer, Hulk ends up throwing it into the sky where Iron Man blasts it into the moon's orbit
Planet Doom Having spent years developing a means of time travel, Doom went into the past and took control of the world, using his knowledge of the future to not only develop advanced technology but also erase the Avengers from history, saving Tony Stark and Bruce Banner from the accidents that would have turned them into Iron Man and the Hulk respectively, keeping Captain America trapped in ice as a sculpture, and enlisting Natasha as the 'Black Bride'. Although Doom believed that he had secured his victory due to humanity's fundamentally low nature, when Thor returned to Earth- immune to the change in history as he was on Asgard at the time- he quickly proved that the Avengers were still the heroes they had been, the group banding together to defeat Doom in the present and send Thor back to the moment when Doom first activated the time machine, Thor subtly sabotaging the machine to make Doom think that it wouldn't work at all.
The Ambassador Nick Fury is ordered by his superiors to have S.H.I.E.L.D. and the Avengers protect Doctor Doom while he is speaking at the United Nations, due to The Cabal wanting to attack him when he did not join them. During a fight with Attuma, Dracula and the Red Skull, but it was actually a ploy to get him to Avengers Tower to improve his tech using the Avenger's. After making it back to Latveria, he discovered that the information he downloaded was a Trojan Horse program as a transmission from the Avengers state that they knew Doctor Doom would try something like this. Captain America then states to Doctor Doom that if he ever leaves Latveria again, he will be arrested. The Trojan Horse program then shuts down Doctor Doom's powergrid for weeks.