Discipline: Economics
A Trust is an entity formed by corporate directors in order to create a monopoly in the companies' sector of operation.
The birth of trusts were in the 19th century, when shareholders of different companies would convey their shares to a board of trustees in exchange of dividend-paying certificates - just so the board would manage all of these companies in a manner which would minimize or totally eliminate competition.
Starting from the end of the 19th century, anti-trust laws gradually eliminated trusts.