Bachelor's degree
Until the 19th century, a bachelor's degree represented the first degree in a particular faculty, with Arts representing undergraduate study, thus the Bachelor of Civil Law (BCL) at Oxford and the Bachelor of Laws (LLB) at Cambridge, for example, were postgraduate degrees. Vestiges of this system still remain in the ancient universities, with Oxford and Cambridge awarding BAs for undergraduate degrees in both arts and sciences (although both award undergraduate BTh degrees through associated theological colleges, and Oxford awards BFA degrees in addition to the BA) and defining other bachelor's degrees (e.g. BPhil, BCL) as postgraduate awards equivalent to master's degrees, although many postgraduate bachelor's degrees have now been replaced by equivalent master's degrees (e.g. LLM for the LLB at Cambridge and MSc for the BSc at Oxford). The same historical usage of indicating an undergraduate degree by it being in the faculty of arts rather than being a bachelor's degree gives rise to the Oxbridge MA and the Scottish MA).
Bachelor's degree
In countries following British tradition, (the University of Malta is an exception) medical students pursue an undergraduate medical education and receive bachelor's degrees in medicine and surgery (MBBChir, MBBS, BMBS, BM, MBChB, etc.).
This was historically taken at the universities of Oxford, Cambridge, and Dublin after the initial BA degree, and in Oxford, Cambridge, and Dublin the BA is still awarded for the initial three years of medical study, with the BMBCh, MBBChir, or MBBChBAO, respectively, being awarded for the subsequent clinical stage of training. Some British universities give a bachelor's degree in science, or medical science, midway through the medical course, and most allow students to intercalate a year of more specialized study for an intercalated Bachelor of Science (BSc), Bachelor of Medical Science (BMedSc), or Bachelor of Medical Biology (BMedBiol) degree with honors.
Although notionally MB and BS are two degrees, they must be taken together. In some Irish universities, a third degree, Bachelor of Arts in Obstetrics (BAO), is added. However, this third degree is an anachronism from the 19th century and is not registerable with the Irish Medical Council. In the UK, these qualifications, while retaining the title of bachelor's degrees, are master's degree level qualifications.