From all hindu texts the Vedas are most ancient, their composition is dated 1500 BCE i.e. more than 2000 years before composition of tantric texts.

Tradition of Bhairava also existed in the Vedic time. All vedic deities are also tantric deities, manifestations of Bhairava, the God who is our Terrifyingly-Blissful Essence.

Aditi in Vedas is Mother of gods, she is Bhairavi or Kali, energy of Bhairava. Aditi is described as both limitless and mother. Vedic gods Yama, Rudra, Soma, Varuna, Indra, Agni being forms of Bhairava also manifest thousands of shaktis around themselves. These shaktis are energies personified as female deities, called mothers. This mothers are pretty martial. Some of martial mothers are manifestations of Yama (i.e. of Bhairava in the form of Yama), some of them are female manifestations of Rudra (i.e. of Bhairava in the form of Rudra), and so on. These mothers are described in a lot of details in 9th book of Mahabharata, Shalyapravan, or Shalya Prava:

The mobile and immobile universe is pervaded by those auspicious ones. They are Prabhavati, Vishalakshi, Palita, Gonasi, … [and then almost 200 names are listed]. These and many other mothers, numbering by thousands, of diverse forms… Their claws were long, their fangs were large and their lips also were protruding. Of straight forms and sweet features, all of them, endowed with youth, were decked with ornaments. Possessed of ascetic merit, they were capable of assuming any form at will. Having not much flesh on their limbs, they were of fair complexions and endued with splendour like that of gold. Some amongst them were dark and looked like clouds in hue and some were of the colour of smoke. And some were endued with the splendour of the morning sun and were filled with bliss. Possessed of long tresses, they were clad in robes of white. The braids of some were tied upwards, and the eyes of some were tawny, and some had girdles that were very long. Some had long stomachs, some had long ears, and some had long breasts. Some had coppery eyes and coppery complexion, and the eyes of some were green. Capable of granting boons and of travelling at will, they were always cheerful.

Possessed of great strength, some amongst them partook of the nature of Yama, some of Rudra, some of Soma, some of Kubera, some of Varuna, some of Indra, and some of Agni. And some partook of the nature of Vayu, some of Kumara, some of Brahma, and some of Vishnu and some of Surya, and some of Varaha.

Of charming and delightful features, they were beautiful like the apsaras. In voice they resembled the kokila and in prosperity they resembled the Lord of Treasures. In battle, their energy resembled that of Shakra. In splendour they resembled fire. In battle they always inspired their foes with terror. Capable of assuming any form at will, in fleetness they resembled the very wind. Of inconceivable might and energy, their prowess also was inconceivable.

They have their abodes on trees and open spots and crossings of four roads. They live also in caves and crematoriums, mountains and near springs. Adorned with diverse kinds of ornaments and garlands, they wear diverse kinds of attire, and speak diverse languages. These and many other tribes (of the mothers), all capable of inspiring foes with dread … “

These mothers are known as yoginis in tantric hindu texts and also as dakinis in buddhistic texts. From this description it is clear that by their style and temper they represent direct expression of Bhairava who is Terrifyingly Blissful Consciousness. This also means that the vedic deities to whom they relate are also manifestations of Bhairava. This is also confirmed by tantras.

In the time of Vedas there were no much need in spiritual practice because vedic people drank soma, magic beverage which revealed their divine nature right away, and Bhairava with all His Terrifyingly Blissful Glory shined in their consciousness in the form of vedic gods and thousands of martial mothers forming a retinues of these vedic gods.

However then when Bhairava concealed the soma, vedic period ended, and the need in spiritual practices for the revelation of divinity appeared. Find more details in the section Tantric Practice