Vidurā–Putra Saṃvāda: Utsāha, Kīrti, and Kṣātra Resolve
Udyoga-parva 131
राजा कृतयुगस््रष्टा त्रेताया द्वापरस्य च । युगस्य च चतुर्थस्य राजा भवति कारणम्
rājā kṛtayugasraṣṭā tretāyā dvāparasya ca | yugasya ca caturthasya rājā bhavati kāraṇam ||
Vāyu said: The king is the maker of the Kṛta age, and likewise of the Tretā and the Dvāpara; indeed, the king becomes the determining cause even of the fourth age (Kali). In other words, the moral quality of an era is shaped chiefly by the ruler’s conduct and governance.
वायुदेव उवाच