He was most notably the printer of the King James Bible, one of the most influential and important books ever printed in the English language.
He and co-publisher Martin Lucas published the infamous "Wicked Bible", which contained a typographical error omitting the word not from the sentence Thou shalt not commit adultery.
About a year later, Barker and Lucas were fined £300 (roughly equivalent to 33,800 pounds today) and were deprived of their printer's licences.
[2] The fact that this edition of the Bible contained such a flagrant mistake outraged Charles I of England and George Abbot, the Archbishop of Canterbury, who said then: "I knew the tyme when great care was had about printing, the Bibles especially, good compositors and the best correctors were gotten being grave and learned men, the paper and the letter rare, and faire every way of the beste, but now the paper is nought, the composers boyes, and the correctors unlearned.
In spite of working on what should have been very lucrative business, Robert was not a good businessman and it may well have been this lack of experience and desperation that led him into trouble with the law, not to mention the controversy surrounding the Wicked Bible and resultant fine.