This is a relic of old times.

Every bank was supposed to be necessarily, more or less, in opposition to every other bank--banks in the same place to be especially in opposition.

In consequence, in London, no banker has a chance of being a Bank director, or would ever think of attempting to be one.
I am here speaking of bankers in the English sense, and in the sense that would surprise a foreigner.

One of the Rothschilds is on the Bank direction, and a foreigner would be apt to think that they were bankers if any one was.

But this only illustrates the essential difference between our English notions of banking and the continental.