History behind Fateh

When Sikhs fought and won their first battle every Sikh was saying

Khalsa ji ki fateh
Khalsa ji ki fateh

But Shri Guru Gobind Singh Ji said this is the victory of truth, this is the victory of God (Waheguru) and Khalsa is of Waheguru. He said it will be

Waheguru ji ka Khalsa.
Waheguru ji ki fateh.

From then it is like so.

Waheguru ji ka Khalsa
Waheguru ji ki fateh
Tajinder Singh