Charles XIII is one of the most interesting political figures in Swedish history. Active during the turbulent years around 1800, characterized by the French Revolution and the Napoleonic Wars, the Enlightenment and Romanticism, he was apparently torn between loyalty to his princely birth and the new ideals of freedom. At the same time, he was a deeply devout Christian with an affinity for the mystical, and a driving force in the transformation, or perhaps more accurately the creation, of the Swedish Masonic Order. Towards the end of his life, he - the last Gustavian - became Sweden's first constitutional monarch under the new constitution of 1809. Although Karl XIII was active at the centre of power throughout his life, during one of the most tumultuous periods of Swedish history - a period that included three coups d'état, a royal assassination, a royal deposition and the lynching of the state's highest official in 1810, as well as four revolutionary war enterprises - he has never before been biographed in its entirety. A biography would thus fill a function and a gap in Swedish history.