Most textbooks date the establishment of the "Publicity Bureau" in 1900 as the start of the modern public relations (PR) profession. Of course, there were many early forms of public influence and communications management in history. Basil Clarke is considered the founder of the PR profession in Britain with his establishment of Editorial Services in 1924. Academic Noel Turnball points out that systematic PR was employed in Britain first by religious evangelicals and Victorian reformers, especially opponents of slavery. In each case the early promoters focused on their particular movement and were not for hire more generally.
Propaganda was used by both sides to rally domestic support and demonize enemies during the First World War. PR activists entered the private sector in the 1920s. Public relations became established first in the U.S. by Ivy Lee or Edward Bernays, then spread internationally. Many American companies with PR departments spread the practice to Europe after 1948 when they created European subsidiaries as a result of the Marshall Plan.
The second half of the twentieth century was the professional development building era of public relations. Trade associations, PR news magazines, international PR agencies, and academic principles for the profession were established. In the early 2000s, press release services began offering social media press releases. The Cluetrain Manifesto, which predicted the impact of social media in 1999, was controversial in its time, but by 2006, the effect of social media and new internet technologies became broadly accepted.