This book analyses the unique constitutional system in operation in Thailand as a continuous process of bricolage between various Western constitutional models and Buddhist doctrines of Kingship. Reflecting on the category of 'constitutional monarchy' and its relationship with notions of the rule of law, it investigates the hybridised semi-authoritarian, semi-liberal monarchy that exists in Thailand. By studying constitutional texts and political practices in light of local legal doctrine, the book shows that the monarch's affirmation of extraordinary prerogative powers strongly rests on wider doctrinal claims about constitutionalism and the rule of law. This finding challenges commonly accepted assertions about Thailand, arguing that the King's political role is not the remnant of the 'unfinished' borrowing of Western constitutionalism, general disregard for the law, or cultural preference for 'charismatic authority', as generally thought. Drawing on materials and sources not previously available in English, this important work provides a comprehensive and critical account of the Thai 'mixed constitutional monarchy' from the late 19th century to the present day.