Alpín mac Echdach

Alpín mac Eochaid may refer to two persons. The first person is a presumed king of Dál Riata in the late 730s. The second is the father of Kenneth MacAlpin (Cináed mac Ailpín). The name Alpín is taken to be a Pictish one, derived from the Anglo-Saxon name Ælfwine; Alpín's patronymic means son of Eochaid or son of Eochu.

Alpín father of King Kenneth
Irish annals such as the Annals of Ulster and the Annals of Innisfallen name Kenneth's father as one Alpín. This much is reasonably certain.

The Chronicle of the Kings of Alba usually begins with Kenneth, but some variants include a reference to Kenneth's father: "[Alpín] was killed in Galloway, after he had entirely destroyed and devastated it. And then the kingdom of the Scots was transferred to the kingdom [variant: land] of the Picts."

John of Fordun (IV, ii) calls Kenneth's father "Alpin son of Achay" (Alpín son of Eochu) and has him killed in war with the Picts in 836; Andrew of Wyntoun's version mixes Fordun's war with the Picts with the Chronicle version which has him killed in Galloway.

Alpín of Dál Riata
The genealogies produced for Kings of Scots in the High Middle Ages traced their ancestry through Kenneth MacAlpin, through the Cenél nGabráin of Dál Riata to Fergus Mór, and then to legendary Irish kings such as Conaire Mór and the shadowy Deda mac Sin.

These genealogies, perhaps oral in origin, were subjected to some regularisation by the scribes who copied them into sources such as the Chronicle of Melrose, the Poppleton Manuscript and the like. Either by accident, or by design, a number of kings were misplaced, being moved from the early 8th century to the late 8th and early 9th century.

The original list is presumed to have resembled the following:
 * 1. Eochaid mac Domangairt
 * 2. Ainbcellach mac Ferchair
 * 3. Eógan mac Ferchair
 * 4. Selbach mac Ferchair
 * 5. Eochaid mac Echdach
 * 6. Dúngal mac Selbaig
 * 7. Alpín
 * 8. Muiredach mac Ainbcellaig
 * 9. Eógan mac Muiredaig
 * 10. Áed Find
 * 11. Fergus mac Echdach

After modification to link this list of kings of Dál Riata to the family of Kenneth MacAlpin, the list is presumed to have been in this form:
 * 1. Eochaid mac Domangairt
 * 2. Ainbcellach mac Ferchair
 * 3. Eógan mac Ferchair
 * 8. Muiredach mac Ainbcellaig
 * 9. Eogan mac Muiredaig
 * 10. Áed Find
 * 11. Fergus mac Echdach
 * 4. Selbach mac Ferchair (called Selbach mac Eógain)
 * 5. Eochaid mac Echdach (called Eochaid mac Áeda Find)
 * 6. Dúngal mac Selbaig (name unchanged)
 * 7. Alpín (called Alpín mac Echdach)

However, the existence of the original Alpín is less than certain. No king in Dál Riata of that name is recorded in the Irish annals in the early 730s. A Pictish king named Alpín, whose father's name is not given in any Irish sources, or even from the Pictish Chronicle king-lists, is known from the late 720s, when he was defeated by Óengus mac Fergusa and Nechtan mac Der-Ilei. For the year 742, the Annals of Ulster are read as referring to the capture of "Elffin son of Crop" (the former reading had besieged rather than captured). Whether Álpin son of Crup is related to the Álpin of the 720s is unknown.