Law issued by Louis IX [France]: “Because we want the Jews to be recognizable and distinguished from the Christians, we command […] every Jew of both sexes to wear badges: A wheel of yellow cloth of rag, that needs to be sown on the outer garment, on the chest and the back to ensure the visibility. This wheel has to be four fingers wide, big enough to contain one palm of one hand. […]”
Ordonnances des rois de France de la troisième race (The Orders of the Kings of France of the third race); Paris 1723, tome I, page 294. Translation by Franziska Wagener