A process for the production of C.sub.4 olefins, which may include: contacting a hydrocarbon mixture comprising alpha-pentenes with an isomerization catalyst to form an isomerization product comprising beta-pentenes; contacting ethylene and the beta-pentenes with a first metathesis catalyst to form a first metathesis product comprising butenes and propylene, as well as any unreacted ethylene and C.sub.5 olefins; and fractionating the first metathesis product to for an ethylene fraction, a propylene fraction, a butene fraction, and a C.sub.5 fraction.