Sen (Bengali: সেন) is a native Bengali Hindu surname derived from "Sena", the Sanskrit word for "army".
The surname is commonly found in the Bengal region of the Indian Subcontinent; namely Bangladesh & West Bengal, India mainly among Bengali Baidya and Kayastha[1] communities. The Sena kings of Bengal claimed themselves as Brahmakshatriya or Kshatriya in their own inscriptions.[2] The surname is also found among some other castes of Bengal like Suvarna Banik, Gandhabanik and Teli.[3][4]