I think it might have originated in the Bible. Paul says in Titus 1:12-13 NIV
"One of Crete’s own prophets has said it: ‘Cretans are always liars, evil brutes, lazy gluttons.’ This saying is true. Therefore rebuke them sharply, so that they will be sound in the faith.
I always found it comical that Paul, the great apostle, endorsed this stereotype of the people of Crete.