Ages of the Children of Ilúvatar
|The History of Arda|
| Years of the Lamps|
Years of the Trees
|Years of the Sun|
| First Age|
|Timeline of Arda|
The First Age of the Children of Ilúvatar began during the Years of the Trees when the Elves awoke at Cuiviénen. This marked the start of the years when the Children of Ilúvatar were active in Middle-earth. Later in the First Age the second kindred, Men, and Ilúvatar's adopted children, the Dwarves, also awoke.
Tolkien wrote that the later Ages lasted about 3,000 years, though this duration was not fixed and he felt that the Ages 'sped up' over time. Each ended following the completion of some major event in the history of the Children of Ilúvatar.
 Other versions of the legendarium
In some texts Tolkien referred to the 'First Age of Middle-earth' or the 'First Age of the World' rather than the 'First Age of the Children of Ilúvatar'. These variations had earlier starting points, extending the First Age back to the creation of Arda, but consistently ended with Morgoth's defeat in Beleriand.
The terms 'First Age of the Sun' and 'Ages of the Sun' are commonly used by many fans, but do not appear anywhere in Tolkien's writings. The 'First Age of the Sun' in this conception is held to begin with the first rising of the Sun and continue until Morgoth's defeat nearly 600 years later. While this is at odds with Tolkien's statements that the first age was the longest by far it is a common misapprehension because the subsequent ages all took place entirely during the Years of the Sun.