I recently came across the Mathematics Genealogy project, which offers a fascinating view of how guidance in doctoral research in maths is passed down from supervisor to student. It's a service currently hosted by North Dakota State University and supported by the Clay Foundation. It's quite a simple idea that can reveal fascinating details about the evolution of subjects studied and 'lineages' of famous mathematicians.
I have an entry, but it's wrong! I did indeed submit a thesis with that long title and study under the guidance of the late Prof. Robert Odoni, but only obtained an M.Sc., having decided after about a year not to continue for the doctorate. The Prof's record is far from complete - he was previously at Exeter University for quite a few years, so I expect he would have had doctoral students there. Also not there yet: he was supervised mainly by Harold Davenport and then towards the end by Alan Baker, both distinguished number theorists.
I do have a Ph.D. in theoretical computer science on 'The Use of Formal Methods for Safety-critical Systems,' for which my supervisor was Dr Kate Norrie, but there's no link shown. That lineage goes through Frobenius, whose work was fundamental to my M.Sc. and before him Gauss, one of the most prolific mathematicians known, and as I write almost 1/3 of all people in the database are his descendants!
It's noticeable that via Odoni, one traces back a UK line of researchers that only goes back as far as the 20th Century, whereas the line via Norrie is mainly German and goes back to the 17th Century. This apparently reflects the fact that in the UK, PhDs were only introduced in the 20th Century. This means that British mathematicians are poorly represented in the genealogy project as it stands, a situation discussed at length in 'The Mathematics PhD in the United Kingdom'. (Incidentally nice to see T. M. Fred Smith mentioned - he kindly acted as my main personal tutor for my B.Sc. at Southampton, even after I later changed my registration and dropped stats in favour of pure maths!)
I've filled in update forms over a week ago, but as yet there have been no changes in the entries of my supervisors or myself. So I'm wondering about improvements...