The Bishops' Bible was a translation of the Bible produced by a committee of bishops of the Church of England in 1568; it was revised in 1572, again in 1577, and then replaced by the King James Bible in 1611.
It was published in response to the Geneva Bible, which had been published by the English Dissenters in 1557 (Old Testament) and 1560 (New Testament), and which included commentary that did not reflect well on the established church. The Geneva Bible was also one of the first Bibles to be printed on a mechanical press and widely distributed to the public, and was disturbingly popular.
For about 40 years, the Bishops' Bible was the official Bible of the Church of England. It was much more grandiose than the Geneva Bible, with over 100 full-page illustrations, but without the commentary of earlier Bibles. It was used as a pulpit Bible in the Church of England, but didn't make much headway against the Geneva Bible in private homes. It also had a number of flaws — it relied heavily on the Great Bible, which had been translated from the Latin Vulgate; there was little collaboration between the various translators, resulting in various inconsistencies in translation; and the Psalms proved difficult to sing, leading the 1572 edition to print the Psalms from the Great Bible alongside the Bishops' translations — and the 1577 edition dropped the new translations altogether.
The King James version fixed these errors, being translated from better sources (a mix of Greek, Aramaic, Latin, and Hebrew), better polished, and being considerably more poetic in form. The church mandated it as the official Bible, and the Bishops' Bible fell quickly into disuse.
The Bishops' Bible is sometimes referred to as the 'Treacle Bible' because it translates Jeremiah 8:22 as "Is there not treacle at Gilead?"; this was changed in the King James version to "balm".