Research Notes:
Moriarty states that, [1] "William Vaux" was "of Bottisham in 1373;" and "alive 1380-81. (Perhaps he did not die until the winter of 1400-1.)" He married "[Joan ?] sister of Sir William Thirning of Lathbury, co. Bucks, and Harrowden, co. Northants, Lord Chief Justice, to whom her grandson was the eventual heir. Perhaps" she was "the Joan Vaux who had licence to have an oratory in her house at Eottisham Lode 1 April 1401. She may also have been a second wife of William Vaux and widow of Maurice Tone of Bottisham Lode. (Cf. Camb. Fines, Case 30, File 92, No. 1.)"
[1] G. Andrews Moriarty, "The Origin of the Vaux Family of Harrowden," Miscellanea Genealogica et Heraldica, Ser. 5, Vol. 5 (1924), 277-301 and 342-362 at 277, [FHLCatalog].