Twelve good men and true
When this phrase was coined, in the early 17th century, 'good' implied distinguished rank or valour. These days people aren't required to be valiant or of high rank in order to be part of a jury. They aren't even required to be men, as women have been called for jury in both the UK and USA since around 1920. This was a consequence of the women's suffrage movement. Prior to the 1920s the opponents of the movement were appalled by the fact that, if women could vote, they could also sit on juries. This was considered worse by some than the right to vote itself. In 1915, the Massachusetts Anti-Suffrage Committee argued, "Jury duty for your wife or your daughter is almost unthinkable. Yet it will be part of her legal duty as a voter."
The 'twelve good men and true' have been referred to since at least the 17th century; for example, in Thomas Randolph's Poems: with The muses looking-glasse; and Amyntas, circa 1635:
"I had rather... haue his twelve Godvathers, good men and true, contemne him to the Gallowes."