Reasons for the Songhai decline

In 1590, al-Mansur took advantage of the recent civil strife in the empire and sent an army under the command of Judar Pasha to conquer the Songhai and to gain control of the Trans-Saharan trade routes. After the disastrous defeat at the Battle of Tondibi (1591), the Songhai Empire collapsed.

Explanation:

to provide for the common defense to form a more perfect union to promote the general welfare

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