From Linesman to Assistant Referee.

It was way back in the 1891 Rules and Laws of Football paragraph 12, where linesmen were first introduced.

"Two linesmen shall be appointed whose duty (subject to the decision of the Referee) shall be to decide when the ball is out of play, and which side is entitled to the corner-flag kick, goal kick or throw-in."

In those early days, linesmen were not neutral, but rather colleagues of the contesting clubs. Because these gentlemen were more than likely to be biased towards their team, they were only given the bare limited responsibilities mentioned in the previous paragraph. These words have stood the test of time, and are still applied (almost word for word) to Club linesmen in this modern age. The words had remained in the Laws (in one form or another), right up to their inclusion within the Laws of Associated Football (LOAF) 'Memorandum on Co-operation' chapter season 1998-1999.

In 1895, it was decided that during games where neutral linesman were officiating, they were allowed to give an opinion on whether a goal was scored or not, and to bring to the referee's attention, any rough play or ungentlemanly conduct that may have escaped his attention.  These neutral linesmen of 1895, were in effect assistant referees, with the emphasis on "assistance" and not "insistence"; and this principle remains today.  But it was not until 1996/97 that this old title of 'Assistant Referee' was eventually introduced into the LOAF.

"Play to the whistle and not the flag".

Before 1891, a raised flag meant that play had to stop, but thereafter was only a form of signal communication intended for the referee's benefit. It took several years for players to become accustom to this change, and hence this is where the origin of the well know phrase, "Play to the whistle and not the flag", originates from!

It was many years later before bright colour was introduced into the flag material. This was the outcome of experience in England, where flame red and bright yellow were adopted from those used in the Army or the Royal Air Force (RAF), as being the most conspicuous in case of need, contrasting best against foliage or misty grey. These bright flags were first used in the international match, England against Belgium at Wembley in 1946.