The Rigveda is the oldest and most significant of the four Vedas. This Veda contains 10,552 verses (collected into 10 books) of hymns and mantras used by the hotri priests.
The hymns of the Rigveda praise many different deities, but the three main ones are: Indra (250 hymns), Agni (200 hymns) and Soma (just over 100 hymns).