Sad I know but I googled it for you and have reproduced the results below.
"The expression 'rob Peter to pay Paul' goes back at least to John Wycliffe's 'Select English Works,' written in about 1380. Equally old in French, the saying may derive from a 12th-century Latin expression referring to the Apostles: 'As it were that one would crucify Paul in order to redeem Peter.' The words usually mean to take money for one thing and use it for another, especially in paying off debts," according to the "Encyclopedia of Word and Phrase Origins" by Robert Hendrickson (Fact on File, New York, 1997) ".In 1546, it was included in John Heywood's collection of proverbs: 'To rob Peter to pay Paul.' George Herbert listed it in his collection (1640) as 'Give not Saint Peter so much, to leave Saint Paul nothing.' First attested in the United States in 'Thomas Hutchinson Papers' (1657). The proverb has its counterparts in other languages. Decouvrir saint Pierre pour couvrir saint Paul (French, 'Strip Peter to clothe Paul'); Desnudar a uno santo para vestir a otro (Spanish, 'To undress one saint to dress another'); Dem Peter nehmen und dem Paul geben (German, 'To take from Peter and give to Paul'). " according to "Random House Dictionary of Popular Proverbs and Sayings" (1996) by Gregory Y. Titelman (Random House, New York, 1996)."
I am thinking that I should get out more.......