Quicksilver

Pietro Maximoff was kidnapped from Serbia and brought to Wundagore Mountain, base of the High Evolutionary, he and his twin sister, Wanda, were the children of Romany couple, Django and Marya Maximoff. The High Evolutionary supposedly abducted the twins when they were babies and experimented on them, once he was disgusted with the results, he returned them to Wundagore, disguised as regular mutants.

As adolescents, Wanda and Pietro discovered that they had unusual superhuman abilities. When Django began to steal food to feed his starving family, enraged villagers attacked the Romani camp. Using his phenomenal speed, Pietro fled from the camp with his sister. The circumstances of their separation from their family were so traumatic that not until well into adulthood could they remembered anything but the barest details of their childhood. For the next few years Wanda and Pietro wandered central Europe, living off the land.

Brotherhood of Evil Mutants
One day, Wanda accidentally caused a house to burst into flame through her hex powers, which she could not yet control. Superstitious townspeople began chasing her, thinking she was a witch. Despite Pietro's attempt to defend her, they were soon overpowered and were about to become victims of mob violence when Magneto came to their rescue. Magneto pressed them into service in his Brotherhood of Evil Mutants, costumed them, and named them the Scarlet Witch and Quicksilver. For months they served Magneto out of a sense of obligation and fear of his reprisal. As members of the Brotherhood, Quicksilver and the Scarlet Witch aided Magneto in his terrorist campaigns against humanity and helped him combat the original members of the X-Men.

Quicksilver found it was relatively easy for him to defeat Cyclops, by simply evading Cyclops' blasts and waiting for Cyclops' energy reserves to be exhausted. However, Quicksilver had no way to counter Marvel Girl's telekinesis. She easily lifted him on the air, spinning him around until he was too dizzy to defend himself.

When Magneto was defeated by the overwhelming powers of the alien Stranger, Quicksilver and the Scarlet Witch quit the Brotherhood; the Stranger transported Magneto away from Earth, and the Maximoff twins returned to Transia.

Joining the Avengers
Pietro and Wanda sought refuge with the Avengers, a world-renowned team of super heroes. They were inducted along with Hawkeye to take the place of the charter members, who wished to take a leave of absence. This foursome was nicknamed "Cap's Kooky Quartet". At first it was looked upon as less capable than the previous roster, but defeating Kang the Conqueror, Doctor Doom, and other threats quickly proved their worth. Although the hot-tempered Quicksilver and Hawkeye often both rebelled against his orders, Avengers leader Captain America molded them into valuable team members.

Humanity's suspicion of mutants still rankled Quicksilver, and he briefly rejoined Magneto after the latter returned to Earth, compelling his sister to come with him. The X-Men and Avengers eventually defeated Magneto.

The Scarlet Witch then began a quest to recover her powers by studying grimoires, with Quicksilver and the Toad supporting her. Her studies accidentally summoned extra-dimensional caudillo Arkon, who kidnapped the Witch to made her his bride, the Toad when he opposed, and then a number of Earth-born scientists in an attempt to use atomic power to save his own world Polemachus even by destroying Earth. Quicksilver gained the help of the Avengers to save his sister, the Avengers managed to save Polemachus without damaging Earth, Arkon ceased any further violence against Earth and renounced to the Scarlet Witch, and Quicksilver and the Scarlet Witch eventually resumed their membership with the Avengers. The Toad chose to remain at Polemachus.

Marriage
Seriously injured during the Avengers' battle against the Sentinels, Quicksilver was taken to medical care by Crystal, a member of the royal family of the hidden race of Inhumans. Months passed before Quicksilver was well enough to contact his companions to tell them what had happened to him. During that time Quicksilver became romantically involved with Crystal, and the two married after a brief courtship. The Inhumans, the Avengers, and the Fantastic Four attended the wedding, held in the Inhumans' refuge of Attilan, then located in the Himalayan Mountains.

Not long after the birth of his and Crystal's first child, Luna, Quicksilver learned the alleged truth about his parentage. Magneto had stumbled upon Bova and learned from her that Wanda and Pietro were supposedly his children.

Confronting Quicksilver and his sister in Attilan with this revelation, Magneto apparently hoped to sway his children to rejoin his crusade against humanity. But Quicksilver denounced Magneto for his callous treatment of them when they were members of his Brotherhood, and refused to believe he had changed his ways.

A man of action, Quicksilver volunte