Cryptic (geology)
The Cryptic era is an informal term for the earliest geologic evolution of the Earth and Moon. It is the oldest (informal) era of the Hadean eon, and it is commonly accepted to have begun close to 4533 million (about 4.533 billion) years ago when the Earth and Moon formed. No samples exist to date the transition between the Cryptic era and the following Basin Groups era for the Moon (see also Pre-Nectarian), though sometimes it is stated that this era ended 4150 million years ago for one or both of these bodies. Neither this time period, nor any other Hadean subdivision, has been officially recognized by the International Commission on Stratigraphy.
Hellenistic Greece
The Hellenistic period began with the wars of the Diadochi, armed contests among the former generals of Alexander the Great to carve up his empire in Europe, Asia, and North Africa. The wars lasted until 275 BC, witnessing the fall of both the Argead and Antipatrid dynasties of Macedonia in favor of the Antigonid dynasty. The era was also marked by successive wars between the Kingdom of Macedonia and its allies against the Aetolian League, Achaean League, and the city-state of Sparta.