Hadean
The Hadean () is a geologic eon of the Earth pre-dating the Archean. It began with the formation of the Earth about 4.6 billion years ago and ended, as defined by the ICS, 4 billion years ago. , the ICS describes its status as ""informal"". Geologist Preston Cloud coined the term in 1972, originally to label the period before the earliest-known rocks on Earth. W. Brian Harland later coined an almost synonymous term, the "Priscoan period", from "priscus", the Latin word for "ancient". Other, older texts simply refer to the eon as the Pre-Archean.
Mycenaean Greece
The Bronze Age in mainland Greece is generally termed as the "Helladic period" by modern archaeologists, after "Hellas", the Greek name for Greece. This period is divided into three subperiods: The Early Helladic (EH) period (c. 2900–2000 BC) was a time of prosperity with the use of metals and a growth in technology, economy and social organization. The Middle Helladic (MH) period (c. 2000–1650 BC) faced a slower pace of development, as well as the evolution of megaron-type dwellings and cist grave burials. Finally, the Late Helladic (LH) period (c. 1650–1050 BC) roughly coincides with Mycenaean Greece.