when was the theravada doctorine codified ?

please help i know it has something to do with Buddhism

I think it was 250BC but not sure.
I am interested in Buddhism but don't know much of the background.

The Therav?da school is ultimately derived from the Vibhajjav?da (or 'doctrine of analysis') grouping which emerged amongst the older Sthavira (or 'teaching of the Elders') group at the time of the Third Buddhist Council around 250 BCE, during the reign of Emperor Asoka in India. Vibhajjavadins saw themselves as the continuation of orthodox Sthaviras and after the Third Council continued to refer to their school as the Sthaviras/Theras ('The Elders'), their doctrines were probably similar to the older Sthaviras but were not completely identical. After the Third Council geographical distance led to the Vibhajjav?dins gradually evolving into four groups: the Mah???saka, K??yap?ya, Dharmaguptaka and the T?mraparn?ya. The Theravada is descended from the T?mraparn?ya, which means 'the Sri Lankan lineage'. Some sources claim that only the Theravada actually evolved directly from the Vibhajjav?dins.

Theravada followers believe doctrines of Buddha as origin . Three months after Buddha enter into Parinirvana or after death doctrine were codified by Sangha group in which Kaspar leads the Arahant monks.