From the mid-sixteenth century, written Scots was increasingly influenced by the developing Standard English of Southern England due to developments in royal and political interactions with England. When William Flower, an English herald, spoke to Mary of Guise and her councillors in 1560, they first used the . When he was , they switched into her native French. King James VI, who in 1603 became James I of England, observed in his work "The Reulis and Cautelis to be observit and eschewit in Scottis Prose" that . However, with the increasing influence and availability of books printed in England, most writing in Scotland came to be done in the English fashion. In his first speech to the English Parliament in March 1603, King James VI and I declared, . Following James VI's move to London, the Protestant Church of Scotland adopted the 1611 Authorized King James Version of the Bible; subsequently, the Acts of Union 1707 led to England joining Scotland to form the Kingdom of Great Britain, having a single Parliament of Great Britain based in London. After the Union and the shift of political power to England, the use of Scots was discouraged by many in authority and education, as was the notion of "Scottishness" itself. Many leading Scots of the period, such as David Hume, defined themselves as Northern British rather than Scottish. They attempted to rid themselves of their Scots in a bid to establish standard English as the official language of the newly formed union. Nevertheless, Scots was still spoken across a wide range of domains until the end of the eighteenth century. Frederick Pottle, James Boswell's twentieth-century biographer, described James's view of his father Alexander Boswell's use of Scots while serving as a judge of the Supreme Courts of Scotland: