This long-established surname is of early medieval English origin, and has two distinct possible sources, each with its own story and derivation. Firstly, the name may be a patronymic form of Aier, itself a nickname for a man who was well known to be the heir to a title or fortune, derived from the Middle English "eir, eyr", heir (Old French "(h)eir", Latin "heres"). One Ralph le Eir was noted in the 1208 Feet of Fines for Essex. The second possibility it that the modern surname is a patronymic of the Middle English personal name "Aier, Aer", itself coming from the Olde English pre 7th Century "Ealhhere", a compound of the elements "eal(h)", old, and "heri", army. Robertus filius (son of) Aier was noted in the 1166 Red Book of the Exchequer, and Robert, grandson of Aer, was recorded in medieval documents of Shropshire, dated 1212. An entry in Blomefield and Parkin's "History of Norfolk" reads, "This year (1510) was Thomas Ayers priest, of Norwich, burnt at Eccles". In the modern idiom the name is spelt Aires, Aiers, Airs and Aers, and recordings of same from London Church Registers include: the christening of Edward Aires at St. Giles' Cripplegate, on September 30th 1646; the christening of Maria Aiers at St. Martin in the Fields, Westminster, on January 8th 1670; the marriage of Elizabeth Airs to Richard Westley at St. Botolph's, Bishopsgate, on July 13th 1697; and Eliz Aers, christened at St. Olave's, Southwark, on October 17th 1732. The first recorded spelling of the family name is shown to be that of Robert Aier, which was dated 1201, in the "Pipe Rolls of Shropshire", during the reign of King John, known as "Lackland", 1199 - 1216. 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.