The town of Mendoza and the province of Álava itself was also a battlefield, where the clashing noble families of the area settled their disputes for generations.
He served as chief huntsman to King Alfonso XI and settled in Guadalajara, which he ruled after marrying the sister of Íñigo López de Orozco.
With the cardinal dead, the family's leadership fell back in power under the constable of Castilla living in Burgos, Bernardino Fernández de Velasco, Santillana's son, an anomaly according to historian, to the detriment of Íñigo López de Mendoza y Luna, Duke of the Infantado, whose house was in Guadalajara.
The same dimensions of power that the cardinal had assured the young generation of the family allowed its members to undertake more independent political careers.
The Mendozas that stayed in Castilla accepted the constable's leadership, but even in this group disputes surfaced, especially between the Infantado and the Count of Coruña, who weakened the family's cohesion as a political and military unit.
The family unit was even more threatened by the acts of two of Santillana's grandson: the cardinal's eldest son Rodrigo, marquis of the Cenete, and the second Count of Tendilla.
The marquis of Cenete and the Count of Cid acted, in all aspects, totally independent from the Mendoza group, stimulated by their haughty and arrogant character.
In 1514 he was accused by the Crown of entering the city of Valencia completely armed, without royal sanction, and in 1523 he joined forces with his younger brother, the Count of Mélito, once again without permission, to quell the Revolt of the Brotherhoods.
The career of Diego Hurtado de Mendoza, Count of Mélito and older brother to the Marquis of Cenete, presents totally different features.
Mélito carried out a moderately important role as viceroy of Valencia during the first years of Charles V's reign, during the Revolt of the Brotherhoods.
Thanks to his uncle's influence, the cardinal of Mendoza, Tendilla was named captain general of the kingdom of Granada and prison governor of Alhambra.
Since he was not the heir to the title of major he was sent to Court, where he prospered and came to occupy important positions, being named as member of the Council of the Kingdom and Main Butler of Margarita de Austria.
During most of the reign of the Catholic Monarchs no serious conflicts arose between the nobles or crises occurred nationally able to test the cohesion of the family.
When probate litigation generated, again, serious conflicts in Castile, Mendoza could not or would not act as a group, particularly Tendilla adopted positions against the rest of the family.