Rösler an haife shi ne a Khánh Hung, Ba Xuyên lardin, a Kudancin Vietnam (yanzu Sóc Trăng lardin, Vietnam) a ranar 24 ga Fabrairu 1973. Babu wani bayani game da Rösler ta Vietnamese haihuwa iyaye ne da aka sani. Ya aka soma daga wani Roman Katolika marayu kusa Saigon da wani Jamus biyu da suka riga da biyu nazarin halittu yara, da kuma kawo Düsseldorf, West Jamus, a cikin wani jirgin sama na yara 'yancin agaji agaji kungiyar Terre des Hommes a lokacin da watanni tara. Ya aka tashe da ya dauki reno mahaifinsa, wanda yake wani soja jami'in, bayan da biyu rabu da lokacin da ya ke hudu.Rösler girma a Hamburg, Bückeburg da Hanover, inda ya sauke karatu daga makarantar sakandare a 1992. Bayan ya zama a yaki likita a cikin Jamus Bundeswehr (a Tarayya Defence Force), Rösler aka yarda da nazarin magani a Hanover.
asibitin Bundeswehr da ke Hamburg