The Qajar Dynasty, ultimately of Turkic origin, seized power from the Zand and Afsharid dynasties, reuniting Persia under one ruler. They went on to re-assert Persian control over large parts of the Caucasus. Wars with an expanding Russia in the nineteenth century, saw the loss of this territory. This was followed by more direct interference in Persia by the Russians and the British. During the First World War, Persia attempted in vain to remain neutral, but had to suffer occupation by Ottoman, Russian and British forces. The last Qajar Shah was deposed by the Reza Shah Pahlavi in 1925.