No, this term is not related to the supposed penurious nature of those living in the north of Britain. Rather, it derives from scot meaning a payment or tax. So to get off scot free is literally to get away without paying taxes. The word appears during the Middle English period and is related to the Old English sceot, a type of coin, but the exact relationship is uncertain. The Middle English word may be the same word, from the Old Norse skot, or it may be a cognate borrowed from the Old French escot. From the 1297 Metrical Chronicle of Robert of Gloucester:
Verst hii wolde ete & drinke...& suþþe þe louerd of þe hous quelle...& suþþe brenne al is hous al uor hor scot ywis.
(First they would eat & drink...& then kill the lord of the house...& then burn all his house, all for their scot, indeed.)
Scot free also appears in the 13th century. From a 13th century manuscript titled The Charter of 1066:
Scotfre and gauelfre, on schire and on hundrede.
(Scot free and stain free, in the shires and in the hundreds.)
Copyright 1997-2013, by David Wilton