What's Hola Mahalla? It's a Sikh festival that usually occurs in March after the Hindu festival of color, Holi.
According to BBC Religion, it started as "a day for Sikhs to practise their military exercises and hold mock battles."
But today, "Sikhs celebrate by watching and partaking in martial arts parades, led by the nishan sahibs of the Gurdwaras. These are followed by poetry readings and music."