Timeline:
969: Prophet Elijah is shown signs of what is to come is shown to a charismatic man named Elijah who is divinely inspired by Rushia who tells him of a near disaster but an even brighter future. He preaches his word and gathers 10,000 followers by 972.

May. 971: First Trekkers (10,000) head off to the east.
They aren’t militant at first, but things change that. Their leaders are Elijah as the religious leader (Who becomes the First Patriarch) and Heraclius Argead, a Charismatic Knight who serves as the secular leader (Who becomes the first King).

August. 971: Land at the island of Argead (This is where the Knight gets his surname), things go along fine at first until the wife of Heraclius is kidnapped and raped by the King of the Island (Dec 971), Aristophane.
A battle occurs where the King is slain by Heraclius in single combat (Jan 972), and the zeal of the Trekkers overcomes their large opponent. As revenge for the sacrilege, the entire island’s population is killed. (By June 972).
Word is sent back home which arrives in November.

Feb 973: Rushia Yab which causes the other trekkers to believe, second and third expeditions are organized.

974: Second Trekkers (25,000) head to this new holy land in May. Arrive in Agread in September, and conquest of the other islands are started. Third Trek organized.

975:
Third Trekkers (35,000) depart in March and arrive in July.
Rest of Islands are taken (October).
The full Prophecy of the Betrayal is revealed to the Trekkers in October after islands fall. They try to send word back, but it is too late.
The plan to take the mainland is prepared.

976: Year of Betrayal and the start of the Great Migration (Feb 24th).
First landing on the mainland (April 24th).
This is where foreigners become officially involved.

977 to 983: Mainland captured totally as more and more Rushians flee.

986: Great Migration over with 1.4 million taken over to their new home, with even more dying.