Abstract
Four years ago I pointed out in an article entitled Die Gestalt der alter Mohammedije in Konstantinopel und ihr Baumeister,1 that the first imperial mosque erected at Constantinople had a shape other than that of the present Fatih. Its shape was not the outcome of direct Byzantine influence as had hitherto been believed but was rather an organic continuation of purely Turkish architectural thought that had arisen in Anatolia. This fact is now confirmed by further documentary evidence which I have been fortunate in finding, and which induces me to return once more to this question so important for the historical development of Turkish architecture. But before I pass on to the new historical documents it is necessary to repeat once more what was said in the above-mentioned article.