[1] García Sánchez developed an active policy of repopulating the new territories and supported the monasteries in the area with large donations, especially San Millán de la Cogolla.

With Sancho III the Elder (CE 1004-1035) the kingdom reached its greatest extent,[5] covering a good part of the northern third of the peninsula, from Catalonia to Cantabria.

Of deep Catholic faith, he founded the monastery of Santa María la Real and names it the episcopal seat of the kingdom, endowmenting it with numerous properties.

He also created the Order of Cavalry of the Pitcher or the Terrace, the first among the peninsular Christian kingdoms; and favored the monastic desks of San Millán, Nájera and Albelda.

[7][6] After the murder of his father, at the age of 14, Sancho Garcés IV (CE 1054- 1076)[3][2][1] succeeds him and is proclaimed in the same field of Atapuerca.

Sancho II, king of León and Castile, invaded the mountains of Oca, La Bureba and Navarre itself, conquering the Plaza de Viana.

The subsequent wedding between Urraca de León and Alfonso I of Aragon temporarily united the crowns of León-Castilla and Aragón-Pamplona, briefly, between 1109 and 1114.