Also known as the 'Age of the Shared Sky'
This age began when the four Old Fleets sent to the North banded together to create the Alliance of Sky Sailors.
Books 1 & 2 happen in the last few years of the Age of the Alliance.
This age ended with the Ravager's War & the Council Massacre, which wiped out almost all of the ranking officers and prompted Captain George Hellman to create the Four Fleets.