San Martín de Albelda, Monastic ruins in Albelda de Iregua, Spain

San Martín de Albelda is a ruined Riojan monastery within the municipal boundaries of Albelda de Iregua, in La Rioja. It was founded on 5 January 924 by Sancho Garcés I and Toda Aznárez and took its name, monasterium Albaidense, from the Muslim fortress of al-Bayadh (the White) on whose site it was built. Its first abbot was named Peter; by 5 January 925 the abbot was Gabellus.

In 924, kings Sancho Garcés I and Toda founded this site to mark the reconquest of Nájera and Viguera from Muslim control. The monastery grew rapidly and became a major center of learning and religious life.

The Codex Albeldensis, copied at the monastery in 976 by the scribe Vigila, holds 430 parchment folios. On folio 12 appear the numerals 1 to 9, the oldest known record of these decimal figures in Europe. The same manuscript shows the earliest images of Spanish monarchs, including Sancho Garcés II and Urraca Fernández, drawn during their lifetimes.

The ruins are easily accessible and can be viewed from outside, with the adjacent active church providing clear orientation. Visitors should note this is an archaeological site, so seeking local information or guided tours helps understand what remains.

The Codex Albeldensis, copied here in 976 by the scribe Vigila, holds the oldest known record in Europe of the numerals 1 to 9, written without a zero. The manuscript also carries the earliest painted portraits of Spanish kings, made during their own lifetimes.