further bloodshed, freeing the Emperor and Caxias to return to the imperial capital. Commander-in-Chief The allies invaded Paraguay in April 1866, but after initial success, their advance was blocked by fortifications at Humaitá by land and along the Paraguay River. The Progressive cabinet decided to create a unified command over Brazilian forces operating in Paraguay, and it turned to the 63-year-old Caxias (made permanent army marshal on 13 January) as the new leader on 10 October 1866. He told his wife that the reason he had accepted the post was because the war "was an evil that has reached more or less all, from the Emperor to the most unfortunate slave." Caxias arrived in Paraguay on 18 November, and assumed the supreme command of land and naval forces in the war. His first measure was to arrange the dismissal of Vice-Admiral Joaquim Marques Lisboa (later the Marquis of Tamandaré and also a member of the Progressive League) by the government, and appoint fellow Conservative Vice-Admiral Joaquim José Inácio (later the Viscount of Inhaúma) to lead the navy. From October 1866 until July 1867, all offensive operations were suspended. During this period, Caxias trained his soldiers, re-equipped the army with newer guns, improved the quality of the officer corps, and upgraded the health corps and overall hygiene of the troops, putting an end to epidemics. Alfredo d'Escragnolle Taunay (later the Viscount of Taunay), who fought in the war, remembered that Caxias was a "generous military chief, who forgave small errors, but was implacable with those who committed grave misdeeds, or, then, who betrayed his confidence." As the Brazilian army was ready for combat, Caxias sought to encircle Humaitá and force its capitulation by siege. To aid the operation, he used observation balloons to gather information of the enemy lines. The combined Brazilian–Argentine–Uruguayan army advanced through hostile territory to surround Humaitá. By 2 November, Humaitá was completely cut off from land reinforcement by Paraguayan forces. On 19 February 1868, Brazilian ironclads successfully made a passage up the Paraguay River under heavy fire, gaining full control of the river and isolating Humaitá from resupply by water. Dezembrada The relationship between the Marquis of Caxias, now the allied Commander-in-Chief, and the governing Progressives worsened until it became a political crisis that led to the cabinet's resignation. The Emperor called Conservatives, under Itaboraí's leadership, back into power on 16 July 1868, while the Progressive League