Vanguard (noun)

1. The position of being at the forefront of new developments or ideas.
2. The leading position in any field or movement.

Origin:

Mid 16th century: from french avant-garde, literally "advance guard", from avant "before" + garde "guard".

Examples:

1. The company was at the vanguard of the green energy revolution.
2. The vanguard of the army was responsible for securing the territory.
3. The vanguard of the protest movement was made up of young activists.
4. The vanguard of scientific research was focused on space exploration.
5. The vanguard of fashion was always one step ahead of the rest.