As Ashdown-Hill found, although he was unable to locate her precisely in the genealogical research that eventually located Michael Ibsen as a mitochondrial DNA match for Richard III, Richard’s sister Margaret Duchess of Burgundy was buried in a Franciscan church in Mechelen, in her Duchy Although it was destroyed during subsequent religious conflicts, a reconstruction has been attempted in the form of a cultural centre (1).
Dr. John Clement, however, can be located more easily in the same town. According to Jack Leslau, Clement was actually Richard, who had been Duke of York until his father’s bigamy was exposed and Lewis fully explores this hypothesis (2). Clement, during his second Low Countries exile, died in 1572 and was buried near the high altar of St. Rombold’s Cathedral.
According to Bing maps, these venues are only a third of a mile apart.
(1) Alive and Well in Canada – The Mitochondrial DNA of Richard III (J. Ashdown-Hill, Ricardian, June 2006, p.8 in particular).
(2) The Survival of the Princes (Ch.11, pp.208-233).