Gaelic texts have been identified dating back to the 6th or 7th centuries, although the oldest reliably sourced manuscript was produced around 1310. Poetry – closely allied to music and song – was by far the dominant medium until into the 18th century, with earlier works largely written in a learned, semi-formal idiom now known as Classical Common Gaelic. As the clan system broke down, and 'amateur' (though usually noble) poets began to enter the field, this was gradually infiltrated, and eventually superseded, by a greater diversity of styles, metres and vernacular language, encompassing courtly love poetry, satire, heroic ballads, bawdry, pastoral and religious verse, in addition to the time-honoured bardic fare of praise-poetry, elegies and historical sagas. As with Scots, however, a strong oral component has always run parallel to, and exerted considerable influence on, the written literature’s development, with Gaelic culture’s rich ballad tradition being a key carrier and conserver of ancient verse compositions.