In 1820 the standard of revolt was raised in Cadiz against the Spanish Bourbons, who, with the aid of the Holy Alliance, had re-established absolutism after the fall of Napoleon. The feeble Ferdinand was compelled to accept a liberal constitution. When the news reached Lisbon the Regency, acting there for King John, was panic-stricken. Communication with Spain was forbidden and word sent off post-haste to John to urge his immediate return to Portugal, or at least the sending of his eldest son, as the only means of pacifying the deep dissatisfaction felt because of the absence of the Court and government. In Porto--always the centre of liberal movements--a formidable conspiracy was formed which included the leading citizens and the officers of the garrison, and in August, 1820, the royal authority was overthrown after scarcely a show of resistance, and a provisional junta installed. The movement spread over the northern provinces and thence to Lisbon, where a junta assumed power in December. After some confusion it was agreed temporarily to adopt the Spanish Constitution, to summon the Cortes, and to retain the Braganza dynasty as constitutional monarchs. The news of the rising in Porto spread like wildfire through the Portuguese possessions beyond sea. Madeira and the Azores immediately installed revolutionary juntas, and some of the Brazilian provinces could not wait until the assembling of the Cortes before establishing free governments. Among native Brazilians and immigrated Portuguese, among soldiers and citizens alike, the enthusiasm for a constitution was well-nigh universal. In Para, Pernambuco, and Rio Grande do Sul, the royal governors were dispossessed by the united soldiers and people, and the Spanish Constitution proclaimed as the law of the land. Rio, however, lay quiet, and it was not until February, 1821, that the Bahia garrison deposed the governor, and installed a provisional junta, which, protesting allegiance to the House of Braganza, proclaimed the Spanish Constitution, nominated deputies to the Cortes, and promised to adopt whatever definite constitution might be framed by that body.