Karin Witkiewicz, also known as Katja Ebstein, (9 March 1945) is a German singer. She was born in Girlachsdorf (now Gniewków, Poland). She achieved success with songs such as Theater or Es war einmal ein Jäger. She was married to Christian Bruhn, who wrote many of her songs. She represented Germany at the Eurovision Song Contest three times: 1970, 1971 and 1980. Her best performance was in 1980 when she gained second place with the entry Theater. As noted by John Kennedy O'Connor in his book The Eurovision Song Contest - The Official History,[1] Ebstein is the most successful performer to have taken part in the contest, without ever winning. She is the only singer to appear in the top three on three separate occasions.