The Campo de San Juan was the seigneurial lordship of the Order of St. John in the lands of La Mancha.
The presence of the Order of St. John in the lands of La Mancha started in 1162 when a number of Knights Hospitallers were donated several villages.
[6] Including the easternmost fringes of the Montes de Toledo in its western part, the territory spanned across an area of 3,983 km2 (2,421 in the current-day province of Toledo and 1,653 in the current-day province of Ciudad Real), limiting in the plains of La Mancha with the Campo de Calatrava (linked to the Order of Calatrava) and the Campo de Montiel (linked to the Order of Santiago).
[8] By 1769, the territory comprised 14 towns: Consuegra, Alcázar, Madridejos, Herencia, Villacañas, Tembleque, Villafranca, Urda, Argamasilla, Quero, Camuñas, Villarta, Turleque and Arenas.
[11] After becoming a mayorazgo-infantazgo in 1785, the langues and assemblies of the Order of Malta were fully incorporated to the Spanish Crown in 1802.