In English, h occurs as a single-letter grapheme (being either silent or representing ) and in various digraphs, such as ch , , , or ), gh (silent, //, /k/, /p/, or /f/), ph (/f/), rh (/r/), sh (), th ( or ), wh (/hw/). The letter is silent in a syllable rime, as in ah, ohm, dahlia, cheetah, pooh-poohed, as well as in certain other words (mostly of French origin) such as hour, honest, herb (in American but not British English) and vehicle. Initial /h/ is often not pronounced in the weak form of some function words including had, has, have, he, her, him, his, and in some varieties of English (including most regional dialects of England and Wales) it is often omitted in all words (see 'h'-dropping). It was formerly common for an rather than a to be used as the indefinite article before a word beginning with /h/ in an unstressed syllable, as in "an historian", but use of a is now more usual (see English articles Indefinite article).
The Roman historian Tacitus wrote in his Agricola, completed in AD 98, that the various groupings of Britons shared physical characteristics with continental peoples. The Caledonians, inhabitants of what is now Scotland, had red hair and large limbs, indicating a Germanic origin; the Silures, inhabitants of what is now South Wales, were swarthy with curly hair, indicating a link with the Iberians of the Roman provinces of Hispania, in what is now Portugal and Spain; and the Britons nearest the Gauls of mainland Europe resembled the Gauls. This is a gross oversimplification which nonetheless holds somewhat true to the present day. Some archaeologists and geneticists have challenged the long-held assumption that the invading Anglo-Saxons wiped out the native Britons in England when they invaded, pointing instead to the possibility of a more limited folk movement bringing a new language and culture which the natives gradually assimilated.
Debate however is ongoing surrounding the ultimate origins of the people of the British Isles. In 2003 and 2006 respectively, Bryan Sykes and Stephen Oppenheimer both championed the idea of continuity ever since the Mesolithic period, with a substantial input from the East during the Neolithic. More recently this view has been contested, by pointing out that the haplotypes which Sykes and Oppenheimer associated with Spain hailed ultimately from Asia Minor. This might be more consistent with some kind of Neolithic wipeout, however it is impossible to date this gene flow. Other theories have proposed an even more substantial input in the Early Bronze Age than was previously thought. Ultimately, the genetics have in fact not yet told us anything new. Researchers at the University College of London have conducted genetic tests which confirm biological differences between the English and the Welsh, with the native English population having DNA which correlates to others found in Germanic parts of Northern Europe traceable through their Y chromosome.