Armenian (endonym: հայերեն, hayeren, pronounced [hɑjɛˈɾɛn] ) is the sole member of an independent branch in the Indo-European language family. It is the native language of the Armenian people and the official language of Armenia. Historically spoken in the Armenian highlands, today Armenian is also widely spoken throughout the Armenian diaspora. Armenian is written in its own writing system, the Armenian alphabet, introduced in 405 AD by Mesrop Mashtots. The estimated number of Armenian speakers worldwide is between five and seven million.