The metric system was created and formalized in 1793 in Napoleonic France. However, who invented it is a tougher question. The idea of a metric system has been attributed to John Wilkins, first secretary of the Royal Society of London in 1668. Several others proposed similar decimalized measurement systems in the intervening years, but it took the Napoleonic decree to make it happen.
The metric system has been around in some form or another since Roman and Greek times. The Romans used to divide armies into tens, hundreds and thousands and the word metre actually derives from the Greek word metron. The earliest recorded use of the word metre in English was in 1797. However, it is actually only since 1960 that the metric system as we know it today has actually been standardised. It had been used throughout Europe for over two centuries before this, but there were variations within the systems and whilst these were actually very miniscule differences, it was decided that there should be a standard metric system. So in 1960, the International System of Units (the Systeme Internationale d'Unites, commonly referred to as SI) was devised in France. This resulted in a baseline metric system where even the tiniest units of measurement are internationally recognised and applied.
Among the first supporters for a metric system was an Englishman, Royal Society founder John Wilkins (1614-1672) in 1668. Gabriel Mouton also supported such a system in 1670.
The foundation for the metric SI system (Système International d'Unités) was the "Metre Convention" signed by 17 countries on May 20, 1875.
