Vela Jiménez who appears also as Vigila Scemeniz, is documented on two occasions as Count of Álava between 882 and 883 in the Codex Vigilanus, compiled in 881 with two large paragraphs added subsequently describing the events that took place in 882 and 883.
There is a previous reference to another count in Álava called Eylo who in 868 led a rebellion that was quashed by King Alfonso III of Asturias and then taken to Oviedo in chains. Nevertheless, the references to Count Vela, the head of this lineage, are much more precise.
He is assumed to have been a member of the royal house of Pamplona and a member of the Jimena dynasty and a relative of King Alfonso III and perhaps his brother-in-law. This placement is based solely on his common patronymic, and there is no documentary evidence whatsoever to support such relationships.
The first count of Castile was Rodrigo who governed the County of Castile by mandate of King Ordoño I of Asturias and, according to documentary sources, it seems that the authority of this Castilian count and later that of his son Diego included parts of Álava, although it was not until 882 when someone held that title.
By 882, the county was being governed by Rodrigo's son, Diego, while Vela Jiménez appears in 882 and in 883 in charge of the government of Álava:Vigila Scemeniz erat tunc comes in Alaba In 882, while Count Diego defended the gorge at Pancorbo, Count Vela was responsible for defending the County of Álava from the castle at Cellorigo, from where he blocked the passage and defeated the Muslim forces led by Al-Mundhir of Córdoba at the Battle of Cellorigo.