An ancient lineage whose origins are not yet clear. For many generations the lords of Vizcaya belonged to this house. The surname Haro was taken by the lords of Vizcaya due to the influence and government they exercised over the place called Haro (Rioja). From the time of Iñigo López Ezquerra, the first historical lord of Vizcaya, the López family had already taken root in La Rioja, not only because of the legacy of their ancestors but also because of the donations received from various monarchs as a reward for services rendered. Lope Iñiguez, son and successor of López Ezquerra, had under his custody the famous castle of Bilibio and with it Haro, as a concession from the King of Navarre, Sancho de Peñalén. The López family would take the toponymic surname of Haro from Diego López de Haro "El Bueno", son of Lope Iñiguez and third historical lord of Vizcaya, to whom King Alfonso VI of Castile gave the village of Haro for his custody, which was demographically increased by the inhabitants of nearby places. In the same reign, he would enjoy the tenure of Nájera, that is to say, of the whole region of La Rioja. The first document in which he appears signing with the surname Haro dates from 1117. From then on, all his descendants would use it. It should be clear that the Lords of Vizcaya did not take this surname because they were the founders of the town of Haro, but because of the government they exercised over it: "The Lords of Vizcaya, although they say that they were settlers of the town of Haro, were not its lords, at least in this respect, as the memoirs of this time (1185) state that they had the lordship of the King, which is the same as saying, its tenure and government" (Garibay: Compendio historial de España, book 19, chap. XIV). The various authors who have studied the genealogies of the house of Haro have encountered the difficulty of its obscure origins. Hence the large number of genealogies that exist (see Labayru: "Historia General del Señorío de Vizcaya", t. II, pp. 45-49 ; Varios: Edad Media y Señores; El Señorío de Vizcaya, Bilbao, 1972, pp. 68-74). This difficulty is overcome in our case, as we study the house of Haro from the time when the family took this surname. For a study of the origins of the López family and the first lords of Vizcaya, see VIZCAYA. The various lords of Biscay were prominent figures in the Haro lineage: Diego López de Haro I (1093-1124), Diego López de Haro II (1170-1214), Lope Díaz de Haro II (1214-1236), Diego López de Haro III (1236-1254), Lope Díaz de Haro III (1254-1288), Diego López de Haro IV (1288-1289), María Díaz de Haro I (1289-1295; 1310-1322; 1326-1334), Diego López de Haro V (1295-1310), Juan el Tuerto (1322- 1326), María Díaz de Haro II (1334-1349), Nuño de Lara y Díaz de Haro (1350-1352) and Juana Núñez de Lara y Díaz de Haro (1352-1359). The Haro lineage formed the head of a faction, competing with the Lara family, especially in the times of Alfonso X the Wise of Castile and his son Sancho IV the Brave. This family exerted a great influence on historical events, especially in the 12th and 13th centuries. Their union with the Castilian kings led to the union of the Lordship of Biscay with Castile, against the interests of the kingdom of Pamplona. A. de Ortueta will tell us: "This dismemberment not only deprived Nabarra of the powerful help that Biscay - by now surely with a relatively important population and resources - could give it, but - this was the truly regrettable thing - it created around itself and its lords a nucleus of attraction that would soon drag in Álava and Guipúzcoa" (A. de Ortueta: Navarra y la unidad política vasca, Barcelona, 1931, p. 255). Ref. Labayru: "Historia General del Señorío de Vizcaya", t. II; L. de Salazar y Castro: Historia genealógica de la Casa de Haro, Madrid, 1920, t. I; Miscellaneous: Edad Media y Señoríos: El Señorío de Vizcaya, Bilbao, 1972; Jesús de Leza: Los López Díaz de Haro, Señores de Vizcaya y Señores de Cameros en el gobierno de La Rioja durante la Edad Media: 1016-1334, Logroño, 1954.