Boyar Ivanko ya kashe Asen a Tarnovo a ƙarshen shekara ta 1196. Ba da daɗewa ba Theodor-Peter ya tara sojojinsa, ya gaggauta zuwa garin kuma ya kewaye shi.Ivanko ya aika da manzo zuwa Konstantinoful, yana kira ga sabon Sarkin Byzantine , Alexios III Angelos, ya aika masa da ƙarfafawa.Sarkin ya aike da Manuel Kamytzes don ya jagoranci sojoji zuwa Tarnovo, amma tsoron da aka yi na kwanton bauna a kan tsaunuka ya kai ga barkewar wani hari kuma sojojin sun tilasta masa komawa.Ivanko ya gane cewa ba zai iya kare Tarnovo ba kuma ya gudu daga garin zuwa Constantinople.Theodor-Peter ya shiga Tarnovo.Bayan ya mai da kaninsa Kaloyan sarkin garin, sai ya koma Preslav.An kashe Theodor-Peter "a cikin yanayi mara kyau" a shekara ta 1197. "An kashe shi da takobin wani ɗan ƙasarsa", bisa ga rikodin Choniates.Masanin tarihi István Vásáry ya rubuta cewa, An kashe Theodor-Peter a lokacin tarzoma;Stephenson ya ba da shawara, sarakunan ƙasar sun kawar da shi, saboda kusancinsa da Cumans .