The Qajar-era refers to a period in Iranian history from 1789 to 1925, marked by the rule of the Qajar dynasty. This era began when Agha Mohammad Khan Qajar unified Iran and established Tehran as the capital. The Qajar rulers faced numerous challenges, including foreign invasions and internal strife, which influenced the political landscape of the region. During the Qajar-era, significant cultural developments occurred, including advancements in Persian art and literature. The period is also known for its architectural achievements, such as the construction of the Golestan Palace. The Qajar dynasty ultimately ended when Reza Shah Pahlavi established the Pahlavi dynasty in 1925.