He is the first guru to be what you could call a warrior saint. He is famous for wearing two swords, one to represent his authority in the spiritual realm, and another to represent his authority in the temporal realm. He also has the longest tenure as guru. At Guru Hargobind's death, his grandson, Guru Har Rai, becomes guru. After his death, his very young son, Guru Har Krishan, becomes guru, but dies of smallpox. After which, Guru Hargobind's youngest son becomes guru. He is named eventually Guru Teg Bahadur, which means brave sword or brave wielder of the sword, because as his father, Guru Hargobind, fought the Mughals, he was known as being unusually brave and an unusually competent warrior.