A descendant of Russian royalty, Natasha Romanov was abandoned as a child and found by soldier Ivan Petrovich. A ballerina in her youth, she joined Russia's K.G.B. and became an elite intelligence operative, a combination of consummate skill and classified government enhancements of her natural abilities. She also became infamous as an often-wed, often-widowed heartbreaker whose husbands (beginning with test pilot turned intelligence agent Alexi Shostakov) tended to suffer "unfortunate accidents", a quirk which may have influenced her choice of long-term code name: the Black Widow. She eventually embarked on a lucrative freelance spy career, which culminated in her infiltration of New York City's Latverian Embassy.
Manipulating the naïve young superhero Spider-Man into helping her escape Latverian security, Natasha used the information she gathered to audition successfully for the American-based international spy agency S.H.I.E.L.D. She became a mainstay of S.H.I.E.L.D.'s black ops division, often partnered with Hawkeye (Clint Barton).
After Hawkeye and the Widow led the successful extermination of over five hundred Chitauri extraterrestrial subversives, the duo was promoted to the ranks of the Ultimates]], S.H.I.E.L.D.'s celebrity super-agents, with newly falsified personal backgrounds. Alongside the Ultimates, Black Widow helped save Earth from a Chitauri plot. She and teammate ]]Iron Man (Ultimate) (wealthy playboy genius Tony Stark) became lovers during the struggle, and later began dating seriously, despite Natasha's mutually hostile relationship with Stark's caustic butler, Edwin Jarvis.
Giving Natasha the female equivalent of his Iron Man battle armor, Stark asked her to marry him and she said yes; however, the bloody massacre of Clint Barton's entire family by a secret traitor within the Ultimates cast a pall over Tony and Natashas' wedding preparations.
While in bed with Tony on the morning of the Liberators' attack, Natasha pulled a gun from under her pillow and killed Jarvis, and then proceeded to point the weapon at Tony. Tony then proceeded to activate the nanites in her bloodstream (the ones that allowed her to control her armor), paralyzing her, and then struck her in the head with a champagne bottle.
After the Ultimates defeated Loki and the Liberators, Natasha was seen recovering in a nearby hospital. However, as soon as she woke up, Hawkeye entered, and killed her, finally getting revenge for the murder of his wife and kids.