From Middle English facioun, from Anglo-Norman, from Old Northern French féchoun (compare Jèrriais faichon), variant of Old French faceon, fazon, façon (“fashion, form, make, outward appearance”), from Latin factiō (“a making”), from faciō (“do, make”); see fact. Compare faction, a doublet of fashion.
From Wiktionary
Middle English facioun from Old French façon appearance, manner from Latin factiō factiōn- a making from factus past participle of facere to make, do dhē- in Indo-European roots
From American Heritage Dictionary of the English Language, 5th Edition
