The authority of a leader derived from a constitution is

The sociologist Max Weber classified authority into three types: traditional, charismatic, and legal-rational. Authority derived from a constitution falls under legal-rational authority.

Legal-rational authority rests on established laws, rules, and procedures rather than on the personal qualities of a leader or inherited custom. A leader who governs under a constitution draws legitimacy from the legal framework that defines the office, its powers, and its limitations. The authority belongs to the office, not to the individual who occupies it.

Charismatic authority derives from the exceptional personal qualities, heroism, or persuasive ability of a leader. Traditional authority is based on long-standing customs, hereditary succession, and established practices (as seen in monarchies and chieftaincies). Delegated authority refers to powers transferred from a superior body to a subordinate one and does not describe a type of legitimacy in Weber's classification.

Constitutional governance is the clearest example of legal-rational authority, where leaders are bound by codified rules and can be held accountable through legal processes.