Genealogy is really interesting. One of my family killed a King, others owned a castle and an island in Scotland – we were clearly better off in those days! You might even find unclaimed inheritances in the last 30 years, so it could be rewarding financially too.
That said, we often have to indulge in a spot of geneology (or heir hunting) where it is not certain who should inherit under a Will or intestacy (no valid Will.) All sort of issues can arise and inheritances can be lost and won through (for example) adoption. Even wider issues can some up now that the 1975 Provision for Family and Dependants Act has been updated.
More on geneology and heir hunters.