When, after concentration, King Uttānapāda saw that Dhruva Mahārāja was suitably mature to take charge of the kingdom and that his ministers were agreeable and the citizens were also very fond of him, he enthroned Dhruva as emperor of this planet.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
वीक्ष्योढवयसं तं च प्रकृतीनां च सम्मतम् । अनुरक्तप्रजं राजा ध्रुवं चक्रे भुवः पतिम्
vīkṣyoḍhavayasaṃ taṃ ca prakṛtīnāṃ ca sammatam | anuraktaprajaṃ rājā dhruvaṃ cakre bhuvaḥ patim
SB 4.9.66