In 2003, Ashdown-Hill was asked by colleagues in Belgium to seek the
mitochondrial DNA (mtDNA) sequence shared by
Richard III of England and his brothers and sisters as one of them,
Margaret of York, had died and was buried in
Mechelen in what is now Belgium. He spent a year tracing an all-female line of descent from Richard III's eldest sister, Anne, to Joy Ibsen, a woman living in Canada. In 2005 he announced the discovery of the
Mitochondrial DNA sequence of Richard III and his siblings, and in 2006 he gave a presentation on the subject of his DNA research to the
Richard III Society in London, in the presence of
Prince Richard, Duke of Gloucester. In 2004, Ashdown-Hill was commissioned by the
BBC to research a story that Richard III's remains had been thrown into the
River Soar in
Leicester. He concluded that the story was untrue. In 2009,
Philippa Langley invited Ashdown-Hill to lead a study day for the Scottish Branch of the Richard III Society, as a result of which the
Looking for Richard project was formally founded at the Crammond Inn, Edinburgh. In August 2012, after three years of work persuading the authorities in
Leicester, the search for the lost remains of Richard III began with the excavation of the Social Services Department car park. On the first day of the dig (25 August 2012) bones which proved to be those of Richard III were found in the area predicted by Ashdown-Hill and Langley and several earlier researchers, such as David Baldwin. Subsequent DNA research and analysis by
Turi King and her colleagues proved that the mtDNA of the bones matched the sequence from Richard III's mother's female descendants that Ashdown-Hill had identified in 2004. On 5 September 2012, Ashdown-Hill had the honour of carrying the remains from the car park. He covered the box of bones with his modern copy of the
House of Plantagenet Royal Standard. In May 2014, Ashdown-Hill's key role in the finding of Richard III's remains was formally acknowledged by
Heather Hallett and her colleagues in the High Court Judgement regarding the reburial of the king's remains. Ashdown-Hill was awarded an
MBE in the
2015 Queen's Birthday Honours for "services to historical research and the exhumation and identification of Richard III". Ashdown-Hill died on 18 May 2018, after living with
motor neurone disease for some time. == Other historical research ==