Don Agustín de Iturbide y Green, Prince of Iturbide (2 April 1863, in Mexico City, Mexico – 3 March 1925, in Washington, D.C.) was the grandson of Agustín de Iturbide, the first emperor of independent Mexico, and his consort Empress Ana María. He became the adopted son, along with his cousin Salvador de Itúrbide y de Marzán, of Mexico's only other royal heads of state—Emperor Maximilian I of Mexico and Empress Carlota of Mexico. After the death of Emperor Maximilian in 1867, he became the Head of the Imperial House of Mexico, but he had no children. His claims passed to Maria Josepha Sophia de Iturbide, the daughter of his cousin, Salvador.
Iturbide was the son of Emperor Agustin's second son, H.H. Prince Don Ángel María de Iturbide y Huarte (2 October 1816 – 21 July 1872). His mother was Alice Green (c. 1836 – 1892), daughter of Captain John Nathaniel Green, granddaughter of US Congressman and Revolutionary War General Uriah Forrest, and great-granddaughter of George Plater, Governor of Maryland.
When Maximilian and Carlota ascended the throne of Mexico in 1863 with the support of the French troops of Napoleon III, the new monarchs invited the Iturbide family back to Mexico. As it became clear that Maximilian and Carlota could have no children together, they offered to adopt Iturbide, which was agreed to with enthusiasm by his father and reluctance by his mother. Iturbide and his cousin were granted the title of Prince de Iturbide and style of Highness by imperial decree of 16 Septiembre 1865 and were ranked after the reigning family.
With the overthrow of the second Mexican empire in 1867, Iturbide's biological parents took him first to England and then back to the United States, where they settled in Washington, DC. When he came of age, Iturbide, who had been graduated from Georgetown University, renounced his claim to the throne and title and returned to Mexico. He then served as an officer in the Mexican army. But in 1890, after publishing articles critical of President Porfirio Díaz, he was arrested on charges of sedition and sentenced to fourteen months of imprisonment. After release from prison, Iturbide was sent into exile, where he suffered two severe nervous breakdowns that resulted in his believing that he would be assassinated. Eventually, he returned to Georgetown University, as a professor of the Spanish and French languages.
For some years before his marriage, Iturbide lived at a monastery near Washington, DC, where he worked as a translator.
In 1894, he married firstly Lucy Eleanor Jackson (1 January 1862 – 11 May 1940, in Epsom, Surrey, UK), daughter of the Rev. William Jackson, by his wife Lucy Catherine Hatchett, of Yealmpton, Devon, United Kingdom.
In July 1915, he married secondly Mary Louise Kearney (25 September 1872, in Washington DC – September 1967), daughter of US Brigadier-General James Kearney.
Agustín de Iturbide y Green died in 1925 in Washington, DC, after suffering a serious nervous and physical breakdown. He was buried at the Church of St John the Evangelist, in Philadelphia, Pennsylvania — alongside his paternal grandmother, Empress Ana María of Mexico.