A Note on Dating:

In the timeline each entry is assigned to one particular date. Many of the periods or sites discussed span a long period of time - in general, they are listed by the date that marks the start of that period. For example, many entries about Archaic Greece, its art and certain sites are listed as 600 BC, the beginning of the Archaic period.

Many of these dates are approximate due to lack of evidence (particularly those from the prehistoric period). Certain dates denote a particular moment in the history of the entry – for example, discussion about imperial Rome has been dated at 27 BC, the year in which Octavian became Augustus; Pompeii has been dated to 79 AD, the date of the eruption of Vesuvius. Some sites, such as Rome and Athens, are listed more than once under a number of dates to reflect the different periods covered.