| The most remarkable external political documents are numerous state treaties, sometimes between equals but more often covenants specifying protectorate or vassaldom status for subordinate states on the fringes of the kingdom. |
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| At times independent, at other times reduced to vassaldom, the first three states were centred on rivers Sogdiana around the Zeravshan and Kashkadarya, Fergana on the lower Syr Darya, and Chorasmia on the Amu Darya's basin. |
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| In some cases a dominating branch replaced the major lineage, and in others a powerful minister formed a strong vassaldom and usurped the authority of the legitimate ruler. |
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| By 1838, the Rozwi Empire, along with the other smaller Shona states were conquered by the Ndebele and reduced to vassaldom. |
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