Marko wa Aretusa (alifariki Aretusa, Syria, 364) alikuwa askofu wa mji huo tangu mwaka 341 au kabla ya hapo. Aliteswa sana katika dhuluma ya kaisari Juliani Mwasi. Gregori wa Nazianzo alimsifu kama "mtu wa pekee na mzee mtakatifu sana". Tangu kale anaheshimiwa na Wakatoliki na Waorthodoksi kama mtakatifu. Sikukuu yake huadhimishwa tarehe 29 Machi. Watakatifu wa Agano la Kale Orodha ya Watakatifu Wakristo Orodha ya Watakatifu wa Afrika Orodha ya Watakatifu Wafransisko In the time of Roman Emperor Flavius Julius Constantius (337-361), Marcus destroyed a heathen temple which under the apostate Emperor Julian he was ordered to rebuild. To avoid this he fled from the city, but eventually returned to save the Christian people from paying the penalty in his stead, and underwent very cruel treatment at the hands of the pagan mob (Sozomen, Historia Ecclesiastica, x, 10) in 362. http://www.santiebeati.it/dettaglio/92999 He is said to have been the author of the Creed of Sirmium (351) and is counted by Tillemont as an Arian in belief and in factious spirit. He was struck from the Roman Martyrology for years, but research by the Bollandists vindicated him and restored his name to the roles.