expression, godan verb (-su)
rise in rebellion; start an uprising
A somewhat literary or historical expression for initiating a revolt or insurrection.
彼らは圧政に耐えかねて乱を起こした。
Unable to endure the tyranny, they rose in rebellion.
More common and neutral term for starting a rebellion; 乱を起こす is more literary and often refers to historical uprisings.
Compound of 乱 (ran, 'revolt, disorder') + を (o, object marker) + 起こす (okosu, 'to cause, to start'). The exact historical derivation is uncertain, but the expression follows a standard pattern for initiating events.