Protesilaus (prō´tĕsĬlā´əs), in Greek mythology, Thessalian prince who was killed in the Trojan War. A prophecy foretold that the first man who touched Trojan soil would be the first to die. When the Greek ships arrived at Troy, Protesilaus leaped ashore and was immediately killed. His wife, Laodamia, mourned his death so excessively that the gods allowed his image to visit her for three hours. When he returned to Hades, she was overcome with grief and took her own life.