Rev. Alban Butler (171173). Volume VIII: August. The Lives of the Saints. 1866.
St. Irchard, or Erthad, Bishop and Confessor in Scotland
ST. PALLADIUS sent Servanus to preach to the northern islands of Orkney, and St. Ternan bishop to the Picts, who is titular saint of the cathedral of Abernethe, and many other churches. St. Irchard was bishop of the Picts about the same time, according to some Scottish historians; but more probably, according to others, about the reign of Malcolm I. See the Breviary of Aberdeen, and Cuper the Bollandist, p. 773.