history of radio spectrum management?

Question

Also brief discussion on latest uk government position on radio spectrum allocation and control

Answer 1

It started after radio stations without regulation in the 1910's and 1920's began to interfere with each other and emergency services who began to use radio found that radio stations could knock them off the air.
Countries began assigning specific frequencies to specific tasks, usually separating emergency services from broadcast and placing specific limits on broadcast power. For example, in the U.S. during the day, there were many small town stations of 1000-10000 watts on the air, but at sunset, these were required to shut down as broadcast conditions improved and clear channel stations that were allowed up to 50,000 watts and assigned frequencies so they could reach a large chunk of the country, like the whole east coast, thus providing radio service to rural areas that were unlikely to have a handy station.
International assignment of frequency bands was required in frequencies that would travel long distances and interfere between nations. Violations of these with "Pirate" stations are still a cause of vexation.