Madrid, while the other liberals were imprisoned. While this was happening in Yucatán, the Plan of Iguala was proclaimed in the current state of Guerrero (at that time part of the Intendency of Mexico). On September 15, 1821, in the Hall of Councils of the City of Mérida, Yucatán declared its independence from Spain. Almost immediately, Governor Juan María Echeverri sent two representatives to negotiate the incorporation of Yucatán into the Mexican Empire. The incorporation into the Mexican Empire took place on November 2, 1821. Republic of Yucatán The Mexican Empire was quickly overthrown (1823) under the Plan of Casa Mata, and the provinces of the erstwhile empire became independent states. The first Republic of Yucatán, declared on May 29, 1823, joined the Federal Republic of the United Mexican States as the Federated Republic of Yucatán on December 23, 1823. The second Republic of Yucatán emerged when the federal pact signed by Yucatán and endorsed in the Constitution of Yucatán of 1825 was broken by the centralist government of Mexico from 1835. In 1841 the state of Tabasco decreed its separation from Mexico and Miguel Barbachano, then governor of Yucatán, sent a commission headed by Justo Sierra O'Reilly to meet with Tabasco authorities to propose the creation of an independent federal republic from Mexico formed by the two states. The idea failed when Tabasco rejoined Mexico in 1842. On August 22, 1846, Mexican interim president José Mariano Salas restored the 1824 constitution and federalism. Two years later, during the government of president José Joaquín de Herrera, Miguel Barbachano ordered the reinstatement of Yucatán to Mexico under the Constitution of Yucatán of 1825. A decisive factor for the reinstatement was the Caste War, which forced Yucatán to seek outside help. In 1852 due to internal struggles between opposing political factions, the Territory of Campeche was created. On April 29, 1863, during the government of Mexican President Benito Juárez, Campeche gained its current status as an independent state. Flag of the Republic of Yucatán The flag of Yucatán was raised on March 16, 1841. The period of the Republic of Yucatán was the only one in which the banner was officially used by the authorities of Yucatán. Rodolfo Menéndez de la Peña, historian, describes the flag of Yucatán: "The flag of Yucatán was divided into two parts: green on left, the right, with three divisions, red up and down and white in