From Wikipedia
In Britain, as the word 'yobb' came out of the London back slang and into more general English usage, it and latterly 'yobbo' have meant 'working class, adolescent, male person'. Within his own culture, he was not necessarily seen as uncouth, though a person writing about him rather than speaking of him was likely to be of another social class and prone to seeing him as loutish.
Dr. C. T. Onions, an editor of the Oxford English Dictionary, seems not to have noticed the word before he published the XYZ section of the dictionary in 1921 but the later supplement notes the use of 'yob' as meaning 'boy' in the working-class youth context, from 1859. This implies that the word had by that stage come out from the back slang argot into ordinary English usage. In the dictionary supplement's references, it is possible to detect a slow drift in the word's meaning, towards the 'Ruffian' interpretation, the new emphasis becoming clear from about 1927.
'Yobbo' appears from 1922 when its meaning does not clearly emphasize the ruffian. Its meaning drifts clearly towards the 'ruffian' interpretation by 1956, though a reference of 1938 calls a yobbo a 'Street Rough'.
In Britain today this word is sometimes superseded by the newer term "Chav".
How could I have forgotten Chav