Afghanistan is one of the most fundamentally diverse countries in the world. Having undergone multiple regime changes even in the past 100 hundred years, the initial Hotak Dynasty of Afghanistan came into power in 1709. The restoration of Afghanistan as an Islamic Emirate was in 2021. This makes Afghanistan as old as 313 years, and as young as 11 months, depending on how it can be viewed.
Afghanistan's unique geographical position has caused it to adopt various regime changes throughout its history. It has been Independent, under suzerain rule, a Kingdom, a Republic, an Islamic State, an Islamic Republic, and (various times) has been an Islamic Emirate. The most recent constitutional change was on August 15, 2021 - restoring it to an Emirate that was initially created in 1823. In the early dynasties of Afghan history, they warred with their neighboring Arabic states for control over their land and political ideology. In the mid to late 1800s, the British Empire was at its peak, and Afghanistan was warring with British-controlled India in order to defend its land. This occurred well into the start of the First World War, acting as a "trojan horse" between Russia and Britain.
After the end of the 2nd World War, when Afghanistan remained neutral (but was active in building relations with the axis powers), it was largely controlled by Russia and formed the People's Republic. Civil unrest grew after the Soviet withdrawal, and the people's republic collapsed in 1992.
The country of Afghanistan is 315 years old, founded in the year 1709.