###Answer In theory, he was of **Karna** identity. - For practical purposes he was **Kshatriya** - Considering his adoptive parents, he was **Suta** ###Theory His actual name was "Vasusena" or "RAdheya", after his adoptive mother "Radha". > And seeing the child furnished with bright mail and golden ear-rings, the twice-born ones named him Vasusena. [[source]](http://www.sacred-texts.com/hin/m03/m03307.htm) However, it's noted (at least in BRC Mahabharata) that Bhishma [& possibly Vidura] knew the correct identity of RAdheya already. For experienced & knowledgeable person like them, it would have been easy to match his attributes with his biological mother Kunti, whose other sons were 5 PAndavas. My assumption is that, Karna would have possibly named so by such dignitaries only. ###Logic As discussed in [this answer](https://hinduism.stackexchange.com/a/19310/1049), Kunti herself was adopted by her father. Her biological father Sura was from the *Vaishya* class. Kunti was married to the king PAndu, who was from Kshatriya class. Hence all her sons, were considered *PAndava*-s: - Vasusena/RAdheya -- who was abandoned by her before marriage, and adopted by Adhiratha & RAdha - Yudhishthira, Arjuna, Bhima -- her biological children - Nakula, Sahadeva -- children adopted by Kunti, after the death of her biological mother MAdri A child born to a Kshatriya (PAndu) and a Vaishya (Kunti) is considered as "Karna". This was applied to Yuyutsu. > During that year, O king, was begotten upon her by the illustrious Dhritarashtra a son endued with great intelligence who was afterwards named Yuvutsu. And **because he was begotten by a Kshatriya upon a Vaisya woman, he came to be called Karna**. [Above linked answer] --- ###Kshatriya Usually a son carries his biological father's class. However in the case of Niyoga, the son carries his adoptive father's class, which could be PAndu in this case. With that logic, Yudhishtira, Bhima, Arjuna could also be considered "Karna"-s, to be precise. Because all of them were born to Kunti from certain celestial deity. If we consider that, Kunti's own class was changed to Kshatriya after her adoption, then all PAndava-s were Kshatriya-s. ##Suta Karna specifically always recognised himself with his adoptive parents, as discussed [in this answer](https://hinduism.stackexchange.com/a/14173/1049) hence he was considered as *Suta*, usually helpers to the Kshatriya kings. > And it came to pass that at this time a Suta named Adhiratha, who was a friend of Dhritarashtra, came to the river Ganga, accompanied by his wife. [[source]](http://www.sacred-texts.com/hin/m03/m03307.htm) Suta is a subclass, which originates, when a Kshatriya man begets a child to a Brahmana woman: > If a Kshatriya begets a son upon a Brahmana woman, such a son, **without being included in any of the four pure orders**, comes to be regarded as a **Suta** The duties of a Suta are all connected with the reciting of eulogies and encomiums of kings and other great men.