There are 5 eras in the Hofferson Empire
The Pre-Memory Era, the long-forgotten eras from prehistoric times to the Steel Age, which is approximately the mid-1400s (PM.E)
The Steel Age The invention and use of steel The birth and rise of the Hofferson Free Cities, from the mid-1400s to the 1600s (SA.E)
The Steam Age, also known as the Age of Oblivion, when the first steam engine was created by chance, and this resulted in a sudden and drastically rapid technological development, which also contributed to the disappearance and oblivion of old things, including magic. This era lasted from the 1670s to the 1700s. (ST.E)
Industrial Age, The great industrialization The golden age of the Hofferson free cities The development of the present form of society and life This era lasted from 1700-1780 until the great revolution that led to the fall of the separate free cities (IA.E)
Imperial era, the era currently taking place, which began in the 1780s with the establishment of the empire and the imperial state form, and continues to this day. (IM.E)