With the Arab invasion in the year 711, this area was endowed with an important defensive complex, which they called “Al-kasar”, which means Alcázar-fortified palace, leaving the population within the Taifa of Toledo. After its fall in the year 1085, La Mancha became a frontier, the town being conquered and fortified at Christian hands.
The repopulation, management and defense is entrusted to the Military Order of San Juan de Jerusalén, which had been established in La Mancha in 1189, forming the Great Priory of Castilla y León, with headquarters in Consuegra, although in “Alcázar de Consuegra” establishes a priory palace.
In 1241 Alcázar de Consuegra received a population letter with 362 residents. In 1284 the prior Fernán Pérez ordered the construction of a tower as the center of power for the priory, and in 1292 King Sancho IV granted the municipality the title of Villa.
The population of Alcázar lived for many centuries under the guidelines of the Order of San Juan. At the end of the Reconquest, the main reason for the presence of the Military Orders, the dignity of Grand Prior became an honorary and lucrative title, for which the Grandees of Spain fought among themselves. Disputes over possession caused the Pope and the Grand Master of Rhodes to intervene. Carlos I, to put an end to the claims of one and the other, divided the Priory and from Castile to Don Diego de Toledo, based in Consuegra, and León to Don Antonio de Zúñiga, who had Alcázar as head.
The 16th century is the golden age of Alcazar, because with the decline of the town of Consuegra, Alcazar became the capital of the Priory of San Juan. In this same century, the gunpowder factory, the most important in the kingdom, was built in Alcázar (1518).
In 1530 Alcázar de San Juan had 18,480 inhabitants, living in it very rich and leading people, most of whom belonged to the Court. Names such as Cervantes, Valdivielso and Díaz Morante were given; Barroso and Sánchez Cotán, important painters; Juan Cobo and Diego de Torres Rubio, teachers in the East and West Indies. In addition, a tradition from Alcazar has always referred to our town as “the birthplace of Miguel de Cervantes Saavedra”.
In 1532, the convent of San Francisco de Asís, in transitional Gothic style, ordered to be built by Don Diego de Toledo, Prior of the Order of San Juan and Duke of Alba, was blessed. The University of Alcázar was founded in this convent, with the chairs of medicine, theology, sacred history and philosophy.
In 1546 the University and the Council of Alcázar vowed to the Immaculate Conception to free the town from a plague of locusts. So that this vow would not be forgotten, the convent of Santa Clara was built next to the hermitage of the Immaculate Conception, run by Clarisas nuns from Toledo who were in charge of caring for the hermitage. The recipe for the famous Alcázar cakes is attributed to them.
In 1601, Mrs. María de Pedroche donated a manor house to found the convent of San José, also for Clarisas nuns, since the one built years ago was too small due to the influx of Clarisas vocations.
In 1603, by agreement of the Council of Alcázar de San Juan and considering it necessary for its population that had grown considerably, a new church was built on the land where the parish of Santa Quiteria was built, so that it would be larger and more spacious. The plans for this new temple were entrusted to the architect Juan de Herrera, builder of the Escorial, which is why the church is in the Herrerian style.
In 1625 the convent of the Holy Trinity is blessed and consecrated, dedicated to Nuestra Señora de Gracia, baroque in style and run by the Trinitarian priests.
From 1665 to 1670, Prince Don Juan José of Austria, bastard son of Felipe IV with the actress María “La Calderona”, was exiled in the palace of the Order of San Juan for political reasons.
In the 18th century, the Hospitaller Order lost its religious character and became an Order of nobles. The Priory becomes an eldership of infants and princes. In this century, the Gran Prior canal was built, which was very useful for agriculture. In 1742, the Camarín de la Virgen del Rosario was completed in the collegiate church of Santa María, with a square floor plan and Baroque style, with a plinth and ceramic floor from Talavera, following the tradition of Andalusian dressing rooms.
The infant Don Gabriel Antonio de Borbón, who had been named Grand Prior of the Order of San Juan by his father, Carlos III, in 1765, considering that the hospitals that existed in Alcázar were insufficient, ordered the construction of the Hospital de Nuestra Señora de los Angeles, in 1770, on the land now occupied by the Conservatory of Music. Our town also had a Provincial Battalion in 1786. At this time, Alcázar, as the capital of the Priory of the Order of San Juan, enjoyed independence.