Now that we've finished reading Byrne's series of back-ups fleshing out Alpha Flight's origins, we may as well update this timeline. Unfortunately there's no specific information as to when Aurora and Northstar joined the team.
c 38 000 BC: An alien spacecraft crashes in the Arctic, and lures an exiled tribesman to millenia of torture.
1935: Charles Xavier is born to Brian and Sharon Xavier, workers on an American nuclear project never revealed to the general public.
1945: The Trinity nuclear test at Alamogordo on the 16th of July kills Brian Xavier.
1946: Sharon marries Kurt Marko - also at Alamogordo, and blamed by Charles for his father's death - who then moves into the Xavier family home.
c1948: Kurt is killed in a lab accident. Soon after, Xavier discovers his psychic powers.
1953: After joining the army, Xavier (along with Kurt's son Cain) is deployed to Korea.
1957: Ororo Munroe is born.
1958: Jean Grey is born.
1960: The group of mutants assembled to commit evil by staggeringly racist villain The Claw are freed from their captor's bondage. They agree to enter into suspended animation, coming out once every ten years for a week to determine whether mutants have finally overthrown humanity, and if so, to offer their entirely uninformed opinions as to how to rebuild the planet.
1961: Bobby Drake and Kurt Wagner are born.
1962: Xavier meets both Erik Lensherr and Gabrielle Haller, the latter of whom will one day bear him a son.
1964: A crewman is washed from the deck of the trawler Mary D and finds a golden egg on the sea-bed; this rapidly hatches into a hominid girl her finder names Marinna. Piotr Rasputin is born.
1968: Xavier faces Lucifer in Tibet, in a struggle that costs him the use of his legs. Dr Michael Twoyoungmen loses his grandfather and his pregnant wife; the latter of which his young daughter blames on him. Richard Easton finds a ceremonial headband at an archaeological dig in the Arctic, and as a result is requested to and agrees to impregnate Nelvanna, Goddess of the Northern Lights.
1969: Ororo Munroe gives up her life as a street-thief in order to follow a strange compulsion drawing her to the Serengeti. Katherine "Kitty" Pryde is born.
1972: James MacDonald Hudson learns his mechanical suit design is to be used by the US Army in Vietnam; he responds by destroying the blueprints.
1974 James Hudson and Heather MacNeil are married.
1977: Xavier founds the X-Men. Richard Easton returns to the world after impregnating Nelvanna, and quickly goes insane.
1978: Doctor Michael Twoyoungman becomes a shaman (named Shaman, obviously) under the tutelage of his grandfather's ghost. He then aids Nelvanna in giving birth to Snowbird, and fosters the baby.
1979: The true identity of the Hulk is revealed to the world. Walter Langkowski was at college with Bruce Banner, and so is inspired to try his own hand at gamma ray experimentation.
1982: Walter Langkowski triggers the gamma ray bombardment process that mutates him into Sasquatch.