as far as i know the church of st. denis was the first one cosidered to have the gothic structure but before the church of st. denis there were others that were related like the orgival art wich was basically the beganing of the gothic structure like for instance : Near East in pre-Islamic and Islamic architecture  were structurally employed in medieval architecture, and are thus thought to have been the inspiration for their use in France. so there was some kind of background on the construction or the creation i should say of the gothic structure of st denis.