Whilst it is reasonably assumed that there extended from the Merovingian period a long tradition of oral poetry in France which embraced the lyric, hagiography, epic and drama, a tradition which drew on Indo-European traditions, more localised folklore, and historical events, it is certain that vernacular French literature (i.e. what has been set down in letters) owes its emergence entirely to the church. It is doubtful whether the romana lingua of the Strassburg Oaths (as sworn by Louis the German and Charles the Bald in June 842) can really be called French, but the short Sequence of Saint Eulalia (c. 881–2) from the area of Valenciennes is certainly French, as are parts of the Sermon on Jonah, also produced near Valenciennes, towards the middle of the tenth century. A Passion narrative and a Life of St Ledger copied c. 1000 have been preserved in the south-west of France, whilst in the following century we have fragments of Occitan and, from Normandy, two literary masterpieces, the Vie de Saint Alexis and the Chanson de Roland. With the exception of the last two we are dealing with works written in a supra-dialectal koiné or scripta, designed to find favour with supra-regional audiences who could not tackle whatever Latin originals were available. Secular French literature written in a relatively standardised language (ultimately identified with that of the Ile de France) is the product of the twelfth century. It was preceded in England by the curiously precocious literary productions that owed much to the patronage of Henry I and II.