In Western Europe, as early as the 5th century, readings of biblical stories began to be accompanied by 'tableaux' and antiphonal song (religious song/music, like psalms and hymns). They were known as 'tropes'.
These liturgical readings or stories became very popular with the largely illiterate population because they were brought to life in a more accessible way.
Originally the stories would have been told in Latin. As they became more popular vernacular forms emerged. Some stories given in Latin would have had a herald at the beginning who would have given a synopsis of what you were about to see.
Early primitive forms started to include dialogue and dramatic action.
The early writers and performers of these stories were likely to have been monks.
The dramas moved from the church to the exterior churchyard and the marketplace, because of their popularity.
In 1210, Pope Innocent issued an edict forbidding the clergy from acting on a public stage. This had the effect of transferring the organisation of the dramas to the town guilds.
In the hands of the town guilds, various changes were made. Latin texts were replaced for the vernacular. Non-biblical passages were added, including comic scenes, and characterisation became more elaborate.
Image: Copper engraving by David Gee (1793-1872) recreates a 15th century Passion Play (The Trial and Crucifixion of Christ) by the Smiths' Company of Coventry.