The Guanabara Palace in Rio de Janeiro was originally of neoclassical design, its construction started by the Portuguese José Machado Coelho in 1853, initially serving as a private residence until the 1860s. In 1865, it became the residence of Princess Isabel and her husband, the Count d’Eu, hence known as the Paço Isabel.
The War of Paraguay began in December 1864, and it is considered the largest conflict ever to occur in South America to this day. At the time the war started, the Count d’Eu was in Europe and openly expressed his desire to participate in the conflict to Emperor Dom Pedro II. It was expected that upon his return to Brazil, he would immediately head to the front lines, as the emperor himself had appointed him as a general of the Brazilian army.