The "Ages of Alathra" are historical eras, translating into one year real-time (approximately 72 Alathra years per real-time year = one age).
The First Age
Very little is known of the First Age (2020), but that toward the end of this age the nation of Ashina was formed.
The Second Age
The Second Age (2021) saw the rise of the greatest empires in Alathran history, and is the longest and or greatest recorded age in Alathra.
The Third Age
The Third Age (2022) is the age to which we live, an age to which many empires have fallen or lie dormant.
The Fourth Age
The new age.