Complex sentence: The eight canons were called Cardenales, as at Cathedral of Santiago de Compostela, and they alone did services before the altar; this custom was recognised as "immemorial" by Pope Innocent III, in 1209.
Split into simpler sentences: The eight canons were called Cardenales, as at Cathedral of Santiago de Compostela, and they alone did services before the altar. This custom was recognised as "immemorial" by Pope Innocent III, in 1209.