Before becoming the Carlton, in 1912, it was the Guillermen hotel which was already classified, in the XIXth, in the series of the luxury hotels of Vichy: one finds trace of its prestigious guests who stay in the thermal city: countess, viscount, marquis, baron, colonel, adviser to the court of Russia near the Tsar, etc. A new life began in 1912 for the Guillermen, acquired by Joseph Aletti, manager of the Société des grands hôtels de Vichy. He undertook a large-scale restructuring with a new neo-classical façade decorated with balconies and loggias. This eight-story renaissance consists of 300 rooms and 250 bathrooms. The interior decoration was adapted to the new trends but the Carlton was stopped in its splendid momentum by the declaration of the First World War. It was requisitioned as a temporary hospital from August 22, 1914 until December 12, 1916.