Ūrjasvatī, the wife of Prāṇa, gave birth to three sons, named Saha, Āyus and Purojava. The wife of Dhruva was known as Dharaṇi, and from her womb various cities took birth.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
प्राणस्योर्जस्वती भार्या सह आयुः पुरोजवः । ध्रुवस्य भार्या धरणिरसूत विविधाः पुरः
prāṇasyorjasvatī bhāryā saha āyuḥ purojavaḥ | dhruvasya bhāryā dharaṇirasūta vividhāḥ puraḥ
SB 6.6.12