By this time Scots had diverged significantly from its sister south of the border and had become the vehicle for an extensive and diverse national literature. Free variation was a prominent and important feature of the Middle Scots spelling system, however, all writers displayed some greater or lesser degree of consistency in their spelling habits. A literary standard applied but it was less than uniform. From the middle of the 16th century Scots began to become increasingly Anglicized. At the time of King James I, the King James version of the Bible and other editions of the Scripture printed in English became popular. By the late 16th century almost all writing was composed in a mixture of Scots and English spellings, the English forms slowly becoming more common so that by the end of the 17th century Scots spellings had almost disappeared completely. This process took slightly longer in unpublished vernacular literature and official records. After the Union of the Crowns in 1603 the Scots speaking gentry had increasing contact with English speakers and began to remodel their speech on that of their English peers. It was this remodelling that eventually led to the formation of Scottish English.