Aumonier was born in Northwood, Middlesex (now northwest London); his family name is Huguenot (French Protestant).

He exhibited at the Royal Academy of Art in 1899–1900 and was responsible for the architectural decorations of the Victoria Law Courts, Birmingham, during the late 1880s.

Aumonier carved the South Wind on the west side of the North wing (not visible from ground level).

In 1932, Aumonier designed two Art Deco relief sculptures in the foyer of the Daily Express Building in London.

Pennyfare, London Transport's staff journal, explained the image in July 1940: Finchley was on the edge of the royal forest of Enfield, which was hunted by both court and commoner.

The gold for the gilded features was mined in South Africa and the bow was English ash, bent by steam and coated with copper and gilt.