This interesting and unusual name, though curiously Irish in appearance, is in fact of Welsh or French origin. In the former case, the derivation is from the Old Welsh personal name Einoin, anvil, an implement represently stability and fortitude. One, Einion yrth was recorded in ancient Welsh documents, dated 420 A.D., and an Ennian filius (son of) Gieruerth appears in the 1159, "Pipe Rolls of Shropshire". Variant forms of the name recorded are Eynon and Eynun, (Shropshire, 1221); Eignon, (Cheshire, 1284); Anyun, (Berkshire, 1279); Vnyon (Chirk, 1392), and Onnyon (Suffolk, 1568). The derivation in the second case is from the Medieval English "oyn(y)on", ultimately from the Old French "oignon", onion, and originally given as a metonymic occupational name to a grower or seller of onions. In the modern idiom the name is spelt Onion, Onyon, Onian(s), Enion, Inion(s), O'Nion etc., the last mentioned form being altered folk etymology as if of Irish origin. The first recorded spelling of the family name is shown to be that of Thomas Onoiun, which was dated 1279, "The Hundred Rolls of Cambridgeshire", during the reign of King Edward 1, "The Hammer of the Scots", 1272 - 1307. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.