Turban is a symbol of honor and self-respect. The Sikh Army fought their last major battle against the British in 1845. All the Sikh soldiers and generals fought for the respect of turban and beard, which symbolize Sikh way. Shah Muhammad, a great Punjabi Muslim poet and historian, who witnessed that war, writes:

Pishe baitth Sardara(n) Gurmatta kita, koi akal da karo ilaj yaro.
Sherh burshia(n) di sade pesh ayee, pag dahrhia(n) di rakho laaj yaro.
ip`Cy bYT srdwrW gurmqw kIqw, koeI Akl dw kro ielwj Xwro]
Cury,buriCAW dI swfI pyS AweI, p`g DwrIAW dI r`Ko lwj Xwro]
Freely translated, it says :
The Sikh chiefs took a unanimous and firm religious decision (Gurmatta), that they should have sense enough to judge the tenor of Maharani Jind Kaur and the crafty Britishers. They said that they were facing a very shrewd enemy and it was high time for them to save the honor of their turbans and beards (both symbols of self-respect). The Sikh soldiers refused to wear helmets during World War I and World War II. They fought with turbans on their heads. A Sikh would have had to remove his turban to wear a helmet, which could not even be imagined. Many Sikhs received Victoria Cross, one of the most prestigious gallantry awards in the British army, for their bravery. Many Sikhs refused to remove their turban even during their imprisonment. Bhai Randhir Singh, a widely respected Sikh preacher, scholar, and a freedom fighter had to undergo a fast to win his right to wear turban in prison.