The Darbhanga Raj, also known as Raj Darbhanga and the Khandwala dynasty, was a Maithil Brahmin dynasty and the rulers of territories, not all contiguous, that were part of the Mithila region, now divided between India and Nepal.

Mithila, also known as Tirhut, Tirabhukti and Mithilanchal is a geographical and cultural region of the Indian subcontinent bounded by the Mahananda River in the east, the Ganges in the south, the Gandaki River in the west and by the foothills of the Himalayas in the north. It comprises certain parts of Bihar and Jharkhand of India and adjoining districts of the Koshi Province, Bagmati Pradesh and Madhesh Province of Nepal. The native language in Mithila is Maithili, and its speakers are referred to as Maithils.