"Rein/Reign"

Rein: (noun) a long, narrow strap attached at one end to a horse's bit, typically used in pairs to guide or check a horse while riding or driving.
(verb) check or guide (a horse) by pulling on its reins.
"he reined in his horse and waited for her"

Reign: (verb) hold royal office; rule as king or queen.
"King Charles reigns over the UK"
(noun) the period during which a sovereign rules.
"the original chapel was built in the reign of Charles I"

Hope this helps!