Since it came up in the "Who's Who on Earth-Two" thread, I thought I'd post a sampling of its companion piece, "The Earth-Two Chronology." To wit:
Events marked with an asterisk (*) are assumed to occur on or near the release date of the comic in which they are depicted. This notation is used only for those stories that cannot be placed along the timeline by direct statements or other internal evidence within the source material itself. Because these stories are dated using what is admittedly an arbitrary default, this chronology cannot and should not be considered definitive.
For brevity's sake, only those Golden Age stories depicting events directly referenced in the Earth-Two canon are included in the following chronology. With a few key exceptions, only the first Golden Age appearances of Earth-Two super-villains are cited.
The Dawn of Time
The Big Bang. The creative force strikes the primordial atom. Traveling backward in time from 1883, The Spectre and Shathan materialize at the moment of creation. Shathan’s atoms are scattered throughout the nascent universe by the energy released, seeding it with evil [Showcase #61].
Sometime after the Dawn of Time
The Council of Living Stars condemns Aquarius to drift, barely alive, through time and space [Justice League of America #73].
circa 999,800 BC
The extraterrestrial Krull are wiped out by a planetary cataclysm [Mystery in Space #73, World’s Finest Comics #249].
The Paleolithic Age
Traveling backward in time from 1944, Hawkman prevents the murder of history's first artist [All-Star Comics #21].
The Star-Spangled Kid, hurled backward through time from 1951, is rescued by Wildcat, Aquaman of Earth-One and Green Lantern of Earth-One and brought forward through time to 1972 [Justice League of America #100-02].
The caveman who will one day become Vandal Savage gains immortality after bathing in the radiation of a meteor [Green Lantern (Golden Age series) #10, The Flash #137, 151]
c. 7000 BC
Osira and Hefnakhti enter the Earth-Two dimension, landing in a remote corner of Egypt and enslaving its people [Wonder Woman #231].
c. 2700 BC through c. 400 BC
Operating out of the Mesopotamian city of Ur, Nabu the Wise acts as Earth's mystic champion [More Fun Comics #67, 1st Issue Special #9, DC Special Series #10, All-Star Squadron #47, The Flash #305].
Between 2551 and 2528 BC
Vandal Savage sits the throne of Egypt as the 4th Dynasty pharoah Khufu/Cheops [Green Lantern (Golden Age series) #10, The Flash #137]. During his reign, he orders the construction of the first Great Pyramid at Giza. Stripesy, hurled backward through time from 1951, is captured and set to work as a construction slave. Some time later, he is rescued by Hourman, Starman and Batman of Earth-One and brought forward through time to 1972 [Justice League of America #100-02].
Between 2134 and 1668 BC
Khufu, a prince of Egypt during the Middle Kingdom, and his consort Shiera are murdered by the priest Hath-Set [Flash Comics #1, All-Star Squadron #12].
Khalis, a high priest of Anubis, is given a magic amulet by the god and uses its occult power to conquer the city of Bubastis. He is overthrown by Nabu the Wise and mummified alive for his crimes. Anubis grants Khalis “life in death” until such time as he can recover the amulet [1st Issue Special #9].
c. 1250 BC
The Trojan War.
Paris, prince of Troy, is briefly possessed by the spirit of Captain Skull. Traveling backward in time from the Second Century, The Spectre exorcises Skull [[i]The Spectre #1].
Traveling backward in time from 1942 in pursuit of Dr. Wilfrid Doome, the Seven Soldiers of Victory meet Agamemnon, Odysseus and other Homeric personae [[i]Leading Comics #3; [i]All-Star Squadron #29].
Speedy, hurled backward through time from 1951, is captured and magically placed in thrall to Circe. Rescued by The Red Tornado (2) , The Flash of Earth-One and Zatanna thed Magician, he is brought forward through time to 1972 [Justice League of America #100-02].
c. 1000 BC
After 6,000 years of ruling their corner of Egypt, Osira and Hefnakhti are overthrown by the forces of the priest Anankh and mummified alive. Hefnakhti dies some time thereafter but his soul remains earthbound [Wonder Woman #231].
Traveling backward in time from 1944, Starman leads a squadron of helots in battle against the Persian armies of Xerxes, inspiring Leonidas and his Spartan legion to make their legendary stand in the Battle of Thermopylae [All-Star Comics #22].
Between AD 180 and 192
The Roman emperor Commodus is briefly possessed by the spirit of Captain Skull. Traveling backward in time from the 12th Century, The Spectre exorcises Skull [The Spectre #1].
The 6th Century
Arthur Pendragon is crowned king of England. Aided by Merlin the Magician and the Knights of the Round Table, Arthur brings peace and justice to the troubled land.
Merlin creates a suit of impenetrable armor and a winged horse to aid Sir Justin, a Knight of the Round Table, dubbing him The Shining Knight. The Knight and Winged Victory are frozen alive in a glacier during combat with the ogre Blunderbore [Adventure Comics #66, Justice League of America #100, All-Star Squadron #62].
Vandal Savage, traveling backward in time from 1977, secretly takes Arthur’s place at Camelot. The Justice Society of America and The Shining Knight follow Savage backward in time, expose his scheme and restore the rightful king to the throne [All-Star Comics #64-65].
Arthur is ultimately overthrown and Camelot destroyed by the forces of his half-sister Morgan LeFey and his nephew Mordred.