The words, ‘Rājā’ (Raja or king) or ‘Rājan’ (Rajan or king) were used many times in the Ṛigveda (Rigveda). Likewise, the terms such as ‘Adhirāja'(Adhiraja or king) , ‘Samrāt’ (Samrat or monarch) and even ‘Sāvabhouma’ (Sarvabhouma or sovereign) which indicate the the sovereign power of the kingdom, were also used as the titles of the king. Samrāt (Samrat), Swarāt (Swarat) and Ekarāt (Ekarat)- these words were used for the able and independent kings. Even, ‘Sāvabhouma’ (Sarvabhouma or sovereign) imples the same meaning in the Brāhmaṇa (Brahmana) books. But it must be acknowledged that the idea of imperialism in the Vedic age was also implied within this term, ‘Sāvabhouma’ (Sarvabhouma or sovereign). Undoubtedly, there were some exaggerations within the notion of Vedic sovereignty as it was said in the ‘Aitareya Brāhmaṇa (Brahmana) that the word, ‘Sāvabhouma’ (Sarvabhouma or sovereign) belong to the ‘Sāmanta’ (Samanta) or ‘Samanta’ group of words. The king whose province was spread out to the seas, could be called the ‘Sāvabhouma’ (Sarvabhouma or sovereign) Nṛpati (Nripati or king). He was the Ekarāt (Ekarat)-

Ayaṃ samantaparyāyī syāt sārvabhoumaḥ sarvāyuṣaḥ
…samudraparyantāyā ekrāḍiti.

While translating the ‘Aitareya Brāhmaṇa (Brahmana), Rāmendrasundar Trivedī (Ramendrasundar Trivedi) writes- ‘Sāvabhouma’ (Sarvabhouma or sovereign) means up to the end of the land or bhūmi (bhumi)-

Samntaparyāyī syāt sārvabhoumaḥ.

It means that the king of the ‘samudrānta pṛthivī’ (samudranta prithivi) whose possessed land was spread up to the sea could be called ‘Samantaparyāyī Sārvabhouma’ (Samantaparyayi Sarvabhouma).  If the word ‘Sāmanta’ (Samanta) can be taken as synonymous with ‘Sāvabhouma’ (Sarvabhouma or sovereign), it can be said that the king who exercised sovereign reign over the states owned by the Sāmantas (Samantas or landlords) can be called the ‘Sāvabhouma Rājā’ (Sarvabhouma Raja or sovereign king). These ‘Sāvabhouma Rājās’ (Sarvabhouma Rajas or sovereign kings) were also called Ekarāt (Ekarat).

[See Dr. Nrisinha Prasad Bhaduri, Dandaniti, p,80.]