Prologue
A prologue[1] is a literary and theatrical term used in a variety of ways over the ages. Some of the uses refer to a preliminary or introductory part to a speech, article, poem, novel or play.
Its more specific use in theatre dates from the Ancient Greek theatre, and developed various uses in the middle ages, Elizabethan period and later, when it refers to an introductory speech, often in verse, calling attention to the theme of a play or the circumstances of its creation, and in many cases lauding the company's patron. (The term can also refer to the performer who delivers such a preliminary oration.)
In South Africa
The convention whereby a performer (or writer involved with the production) writes or adapts an ad hoc prologue and reads it (or has it read) at the start of an evening's entertainment was apparently brought to South Africa by the amateur players attached to the British Garrison (see Garrison Players). In their case some of the prologues contained social commentary and light mockery, as well as praise for patrons and audiences. It soon became common practice, and in terms of theatre history, these texts are quite possibly some of the earliest examples of local (written) drama in South Africa, leading on to similar practices in local Dutch and Afrikaans theatre. Not many of such texts have been preserved of course, since they were in essence occasional pieces, though some programmes and reviews from the 19th century do contain excerpts from or examples of such Prologues.