There are more than 86,000 mosques in Turkey, 6733 of these being historic mosques. This study aims at developing a novel LED lantern for enhancing the interior illumination of Turkish historic mosques while providing significant energy savings. In order to accomplish this, an LED lantern design is carried out, the photometric results of which are analysed using the world renowned architect Sinan's Semsi Ahmet Pasha Mosque from 1580 as a model. With this lantern, the target is to maintain the recommended illuminances and comfort conditions in the interior of historic mosques while achieving substantial energy savings and, at the same time, preserving the historic structure of the mosque. The study promotes the utilization of modern technologies and brings a novel, energy efficient and sustainable approach to Turkish historic mosques.