The record of the National Fruit Collection, at Brogdale in Kent, describes it1:
Originated at Anjou, France. It was first described in 1608. Fruits have fine, crisp, white flesh with a sweet and aniseed flavour.
Where Fenouillet Gris came from.
Sources
Fenouillet Gris (accession 1948 - 482), National Fruit Collection, Brogdale, Kent (Defra).
Supports: the description quoted; the use; the fruit's size, shape and colours and the flesh, from the collection's characterisation; the picking time at Brogdale (mid october); the other names.