In the epic Mahābhārata, Drona (Sanskrit: द्रोण, droṇa) or Dronacharya (Sanskrit: द्रोणाचार्य, droṇāchārya) was the royal guru to Kauravas and Pandavas. He was a master of advanced military arts, including the Devastras. Arjuna was his favorite student. Drona's love for Arjuna was second only to his love for his son Ashwatthama. He was considered to be a partial incarnation of Brihaspati.
Read more about Drona: Birth and Early Life, As A Teacher, Drona in The War, Yudhisthira's Capture and Drona's Death, Modern Assessment