all my eye and Betty Martin

In Britain during the 1700s, the phrase was a common claim of dismissal (similar to 'nonsense', or 'hogwash'), or a way to declare disbelief of an absurdity. It possibly originated as the punch line of a joke (though this is likely a folk etymology). Most variations of the joke involve a British sailor visiting Italy. He overhears a Latin prayer, "Ah! [Da] mihi, beate Martine" (which translates to "Ah! Grant to me, blessed Martin", referring to St. Martin). The sailor mishears the prayer, and later uses the phrase as "All my eye and Betty Martin".

all my eye and Betty Martin (uncountable)

1. (dated) rubbish, humbug
   • 1881 Thomas Bastard, The Autobiography of Cockney Tom, at Project Gutenberg Australia

     All my eye and Betty Martin, thought I, I will have no more truck with you.

   • 1893 November, R. D. Blackmore, “Perlycross”, in Macmillan's Magazine, volume LXIX, page 83:

     Oh, that's all my eye and Betty Martin! Nobody believes that, I should hope.

   • 1989, Tim Smith, On Land and in the Sea, The Safety Bowl:

     Bins the bowl as he says "Falsehoods and a man of straw is all my eye and Betty Martin saw"

• all my eye