For centuries the most popular boy's name in Britain was John (Jack, as one form of it, still is). It is the name of a saint, a disciple, a gospel and an English king. John Bull is the personification of England.
With characteristic national irreverence, we also use John as a colloquial word for a lavatory and for a prostitute's client.
According to the Office for National Statistics, by the end of this year Mohammad (in all its spellings) will become Britain's commonest baby name.
I suppose we will all have to behave better in future.