'blimey' originates from English, specifically the phrase 'gor blimey', where 'gor' was a euphemism for 'God' and 'blimey' derives from 'blind me' (from the oath 'God blind me').

'blimey' changed from the colloquial expression 'gor blimey' (a minced oath dating from the late 19th/early 20th century) and eventually became the shortened modern form 'blimey'.

Initially it was a literal oath meaning 'God blind me', but over time it evolved into a mild exclamation of surprise without the original literal sense.