Quo warranto challenges authority to hold public office, enabling ouster where legal qualifications or authority are lacking. Quo warranto is a writ challenging a person's legal right to exercise a public office by requiring the holder to show the warrant or authority for appointment. The remedy permits inquiry into the legality of the claimant's title and may be grounded on lack of required qualifications, disqualifications, misuse, or forfeiture. Proceedings examine the legality of holding office irrespective of who made the appointment; appointment by a competent authority does not bar inquiry, and failure to establish valid authority can result in ouster or forfeiture.