Martín Juan de Castejón y Medrano^[1] (b. Soria, November 20, 1604 - d. 17th century) was the V lord of Velamazán, Riotuerto, Los Olmillos, Strong House of Arias and La Serna, Gentleman of the Chamber of His Majesty, Perpetual Councilman of Soria and Almazán.^[2][3]

He was Captain of Infantry in the militias of Agreda, leading them during the siege of Fuenterrabia in 1638. He was aided by Don Pedro Velaz de Medrano, II Lord of Tabuérniga, who commanded his Tercio from Alava in the Franco-Spanish war. Martín was a Gentleman of the Chamber of His Majesty, Perpetual Councilman of Soria and Almazán.^[2]

He entered into marriage in Valencia with Angela Margarita Buenaventura de Belvis y Cabanillas, born in Valencia and baptized in the church of San Juan del Mercado on April 24, 1606. Margarita Buenaventure was the daughter of Pedro de Belvis, Knight of Santiago and first Marquis of Benavites in Valencia, and Leonor de Cabanillas y Mila, both natives of Valencia. Martín Juan made his will through a power of attorney granted to his wife Angela de Belvis on May 1, 1647, before the scribe of Agreda, Diego Pérez.^[2]

Martín Juan de Castejón y Medrano was the son of Martín de Castejón y Andrade, born in Agreda and baptized in the church of Santa María de Yanguas on December 8, 1577, and his wife Dona Inés de Medrano y Mendoza, a native of Soria. His father Martín was the IV Lord of the town of Velamazán, VII of Ibiernas, and of the Strong House of Arias in the lordship of Molina. His father Martín granted a partition deed of his grandfather's assets in 1603. His father was a Gentleman of His Majesty and a Knight of the Order of Alcántara, into which he was admitted on April 29, 1609.^[2]

Francisco de Castejón y Andrade, resident of Noviercas (Soria), established a patronage in favor of his nephew Martín de Castejón, who was married to Inés de Medrano, father and mother of Martín Juan de Castejón y Medrano.^[1]

His mother Inés de Medrano y Mendoza was born into the prominent House of Medrano from Soria, who used her surname Morales by imposition of the entailment of Olmedilla. She was the daughter of Francisco de Medrano y Morales, lord of Olmedilla, and Beatriz de Medrano y Mendoza. Lady Beatriz de Medrano y Mendoza was the paternal granddaughter of Garcí Bravo de Medrano, Lord of San Gregorio, and his wife Catalina de Mendoza. Lady Beatriz de Medrano y Mendoza died in childbirth with her son Martín. Martín de Medrano married Francisca Jinesa Petronila Castejón y Muñoz de Alabiano, connected to the Branch of the Counts of Agramonte. Martín de Medrano made his will in Agreda, through a closed document, on December 8, 1636, formalized by the scribe Juan Fraile.^[2]

The Castejón surname had its cradle and original homestead in the ancient town of Castejón de la Barca (from which it took its name), in the judicial district of Tudela (Navarre). That town disappeared long ago and is now only a depopulated area. From the historical data that remain about it, it is known that it had a castle, which served as defense against the invasions suffered by Navarre from the Castilians, and that in 1244 it was owned by Guillermo Pérez de Castejón, who is the first known bearer of this surname.^[2]

Martín Juan de Castejón y Medrano and Angela Margarita Buenaventura de Belvis y Cabanillas were the parents of:^[1][2]

• Angela Inés de Castejón Medrano y Belvis, born in Soria and baptized in the Collegiate Church of San Pedro on May 2, 1630, who married her relative Gil Fadrique de Castejón.
• Bernardino Antonio de Castejón Medrano y Belvis, baptized in Soria on February 11, 1635, scholar at the College of Santa Cruz in Valladolid, Knight of Alcántara, admitted to the Order on April 9, 1662, Mayor of the Royal Audiencia of Seville in 1663, and of the Royal Council of the Orders.
• Manuel Ignacio de Castejón Medrano y Belvis, born in Agreda and baptized in the parish of Nuestra Señora de Yanguas in that town on February 10, 1642, who entered as a scholar at the College of Santa Cruz in Valladolid and became a Knight of the Order of Santiago on December 16, 1671.
• Francisco Juan de Castejón Medrano y Belvis, born in Agreda and baptized in the church of Nuestra Señora de Yanguas on June 14, 1643, Knight of Santiago since December 16, 1671. He married Juliana Pardo de Nájera y San Martín in 1698, a native of Madrid (daughter of Gil Pardo de Nájera, Knight of Santiago, of His Majesty's Council in matters of Finance and its Tribunals, and Isidora de San Martín).
• Pedro Lorenzo de Castejón Medrano y Belvis, a native of Soria, who died young.
• Juana de Castejón Medrano y Belvis. Nun.
• Teresa de Castejón Medrano y Belvis. Nun.
• Martín Pedro de Castejón Medrano y Belvis, who continues the line.

Martín Juan de Castejón y Medrano's son Martín Pedro de Castejón Medrano y Belvis was a Councilman of Soria and the first Count of Velamazán by the grace of King Carlos II, dated July 4, 1675, and a knight of Calatrava since May 30, 1663. He married doña Teresa Ibáñez de Segovia Isasi de Leguizamón, a native of Bilbao. Martín Pedro de Castejón Medrano y Belvis and his wife Teresa had a son named Martín Manuel González de Castejón Medrano y Ibáñez, I Marquess of Velamazán.^[2]

The famed 17th-century Marquess of Velamazán Palace is situated between Berlanga de Duero and Almazán. Restored entirely, the rural house on the western side of the palace retains its original marble fireplace within a spacious lounge where successive marquises once unwound, until the final one sold the estate to local villagers in the early 20th century, subdividing it into multiple residences. To the south, the primary Renaissance-style balcony facade boasts a sizable stone-carved coat of arms depicting the family insignia, alongside a sundial bearing the engraved date of 1619.^[4]

Martín Juan de Castejón y Medrano's grandson Martín Manuel González de Castejón Medrano y Ibáñez, was the first Marquess of Velamazán and IX Marquess of Lanzarote, perpetual regidor of Soria and a Gentleman of the Chamber of King Carlos II.^[1]

Don Agustin de Herrera y Rojas, II Marquess of Lanzarote married Doña Luisa Bravo de Guzmán in 1622, daughter of Jerónimo de Guzmán and Antonia Bravo del Castillo. Doña Luisa Bravo de Guzmán became the IV Marchioness of Lanzarote, II Countess of Fuerteventura, after the death of her son Agustín de Herrera y Rojas, III Marquis of Lanzarote.^[5]

Luisa Bravo de Guzmán was born in Alcalá de Henares in 1595 and passed away in Madrid on November 24, 1661. The Marchioness Doña Luisa Bravo de Guzman was the granddaughter of Don Pedro de Guzmán, Lord of Olmedilla, and Doña Luisa Bravo de Lagunas, who in turn was the daughter of Garci Bravo de Medrano y Mendoza, Alcaide of Atienza; and his wife Doña Ana Sarmiento de Ayala y Rojas. Luisa Bravo de Guzmán was the great-granddaughter of the noble Garcí Bravo de Medrano y Mendoza.^[5]

Doña Luisa Bravo de Guzmán was succeeded by Don Juan Francisco Duque de Estrada y Bravo de Guzmán, V Marquess of Lanzarote and the great-grandson of Garci Bravo de Lagunas Medrano Mendoza.^[6]

Upon the death of his cousin Pedro Ibáñez de Leguizamón y Segovia, Martín Manuel González de Castejón Medrano y Ibáñez inherited the titles of V Marquis of Gramosa and Viscount of Las Vegas de Matute. King Felipe V granted him, in 1741, for himself and his legitimate successors, the Grandeeship of Spain of the first class.

Martín Manuel González de Castejón Medrano y Ibáñez married twice: first, to his cousin doña Ana Laura de Castejón, and second, to doña Agueda María de Camargo.^[1]

From the second marriage, his son was:^[1]

José Joaquín de Castejón Medrano y Camargo Ibáñez de Segovia, who was the first Count of Fuerteventura by Royal decree of April 19, 1746. He married doña Juana de Salcedo y Río, and from this union were born:

1. María Josefa Nicanora de Castejón Medrano y Salcedo, Jorja de Castejón y Salcedo, wife of the Marquis of Alcántara. The Palace of the Marquises of Alcantara was built at the end of the 17th century and completed in 1704 by Martín Pedro González de Castejón Medrano Belvís y Ibáñez, 1st Marquis of Velamazán, perpetual regidor of Soria. The Counts of Fuerteventura and Marquises of Velamazán, who later received the title of Marquises of Alcántara, is one of the great palaces that the city of Soria preserves, with the influence of Madrid's baroque architecture.

2. Micaela de Castejón Medrano y Salcedo, wife of Agustín de Bracamonte, Marquis of Fuente el sol and Lord of Cespedosa and other estates, aunt and uncle of Don Fernando Vélaz de Medrano, Marquis of Fuente el Sol, Cañete and Navamorcuende, Grandee of Spain, son of Don Jaime José Ignacio Velaz de Medrano y Barros, III Marquis of Tabuerniga.

3. Pedro de Castejón Medrano y Salcedo, who became the second Count of Fuerteventura and Villarreal, married his first cousin doña Ana María de Castejón y Dávila.