Q: I heard you discussing “Bob’s your uncle” on the air. In England, where I lived for many years, the expression was often used at the end of the description of a process, such as giving directions: “Take the second left, then the first right, go halfway down the block, and Bob’s your uncle!”
A: I love that usage. It’s almost like “and there you have it” or “and you’re all set.” How much more interesting than our saying “and there you are” or some such!
As for the origin of the expression, the best explanation I can find is Michael Quinion’s (the following quotation comes from his website, World Wide Words):
“This is another of those catchphrases which seem to arise out of nowhere and have a period of fashion, in this case quite a long one. We know that it began to be used in the 1880s in Britain. One theory has it that it derives from the slang phrase all is bob, meaning ‘all is safe.’ But there have been several slang expressions containing the word bob, some associated with thievery or gambling, and around this time it was also a common generic name for somebody you didn’t know. The most attractive theory is that it derives from a prolonged act of political nepotism. The prime minister Lord Salisbury (family name Robert Cecil ) appointed his rather less than popular nephew Arthur Balfour (later himself to be PM from 1902-11) to a succession of posts. The first in 1887 was chief secretary of Ireland, a post for which Balfour was considered unsuitable. The consensus among the irreverent in Britain seems to have been that to have Bob as your uncle guaranteed success, hence the expression and the common meaning it preserves of something that is easy to achieve.”