Franz Xaver Süssmayr was an Austrian composer and conductor, born on March 2, 1766, in Vienna. He is best known for completing Wolfgang Amadeus Mozart's unfinished Requiem after Mozart's death in 1791. Süssmayr's version of the Requiem has become the most performed and recognized interpretation of this iconic work. In addition to the Requiem, Süssmayr composed various operas, symphonies, and choral works. He studied under Antonio Salieri and was active in the Viennese music scene, contributing to the development of classical music during the late 18th century. Süssmayr passed away on September 17, 1803.