take over the reins

take over/up the reins

to take control of something, especially an organization or a country (often + of ) He took up the reins of government immediately after the coup.

See hand over the reins, tighten the reins

See also: reins, take

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take over the reins

to begin controlling an organization or a country She offered good advice to the new Speaker as he took over the reins of leadership in the House of Representatives.

Etymology: based on the idea that the person who handles the reins (straps) that control a horse has control of the vehicle the horse is pulling

See also: reins, take