The first published history in J.R.R. Tolkien's The Silmarillion is Ainulindalë.
Ainulindalë, meaning the “Music of the Ainur,” is the opening section of The Silmarillion. It describes how Eru Ilúvatar creates the Ainur and invites them to make a great music. The rebellious contributions of Melkor introduce discord, but the resulting vision becomes the foundation for the creation of Eä, the universe.
The section functions as Tolkien’s creation myth and establishes ideas that recur throughout the legendarium: the limits of individual power, the consequences of rebellion and the emergence of a design larger than any one character understands.
Ainulindalë is easy to confuse with the other divisions of The Silmarillion. Valaquenta follows it and describes the Valar and Maiar, while the Quenta Silmarillion tells the central history of the Silmarils and the First Age. Akallabêth comes later and concerns Númenor.