Ardo (or Ardonus, possibly short for Ardabastus; died 720/721) is attested as the last of all Visigothic kings of Hispania, reigning from 713 or likely 714 until his death. The Visigothic Kingdom was already severely reduced in power and area at the time he succeeded Achila II, and his dominions probably did not extend beyond Septimania and present-day Catalonia, due to the Arab conquests of the previous three years.
Ardo is only recorded in one Visigothic regnal list as reigning for seven years. As of 716 the Arabs crossed over the Pyrenees and invaded Narbonensis, the last province under Gothic control. Over the next three years Ardo probably defended what remained of the Visigothic kingdom and he "may have gone down fighting like his predecessor" after the Arabs took Narbonne and before they conquered all that remained of the old kingdom.
If Ardo is to be identified with Ardobastus, then he survived the invasion and negotiated a treaty, wherein he represented Christians as the Count of the Christians of al-Andalus. This title would pass to a number of individuals until the tenth century at least. Other counts included: Rabî’ ibn Theodulph,: 281–294 Abû Sa’îd al-Qûmis, (a descendant of Ardabastus) and Mu’âwiya ibn Lubb.
- Collins, Visigothic Spain, 140.
- Thompson, 251, says he is otherwise unknown.
- Collins, The Arab Conquest of Spain, 45.
- Simonet, Francisco Javier. "Historia de los mozárabes de España (rééd.)." (1983). vol. 4, p. 197, p. 247.
- Vallvé, Joaquín. "The zalmedina of Córdoba." Al-Qantara 2.1 (1981), pp. 277-318.
- AL-QÛTIYYA, I. B. N. "Tarij iftitâh al-Andalus (Historia de la Conquista de España), texto árabe impreso por P. de Gayangos en la Colección de Crónicas Árabes de la Real Academia de la Historia, T. II (Madrid 1868)." Una edición posterior: Historia de la conquista de España de Abenalcotia el Cordobés, trad. castellana de J. Ribera, Madrid (1926). p. 31.
- Molénat, Jean Pierre. "Minorités in miroir. Mozarabes et mudéjars dans la Péninsule Ibérique médiévale." Ethnic-religious minorities in the Iberian Peninsula: Medieval and modern period . Edições Colibri, 2008.