[1] He was born in Dublin, probably at Fishamble Street, the fifth son of Thomas Johnson, an apothecary who in later life qualified as a physician.
[1] Robert's career was destroyed in 1805 when he was convicted of seditious libel and forced to resign from the Bench, for having written a number of pseudonymous letters attacking the Government (the so-called "Juverna" affair).
Robert's disgrace adversely affected William's career, and he had to wait long years before his own elevation to the Bench.
[1] William was educated at Trinity College Dublin, where he graduated Bachelor of Laws in 1784, and entered Lincoln's Inn in 1782.
[1] He was regarded as a much abler lawyer than his brother, and was generally respected, although critics said that he could be arrogant, morose, coarse and bad-tempered.