In Hinduism, Akhara (also akhada) is an association of the different sects of Yogis, also known as Sadhus (Hindu Renunciates). Its history dates back to the eighth century when Adi Shankaracharya established seven Akharas. Some yogis revere Gorakhnath as the founder rather than Shankaracharya. The 7 ancient Akharas are Mahanirvani, Niranjani, Atal, Avahan, Agni and Anand Akhara. Today there are 3 major Akharas (Juna, Mahanirvani and Niranjani) and 3 minor Akharas (Atal affiliated with Mahanirvani, Anand affiliated with Niranjan). Traditionally during the Kumbh Mela, the Naga Sadhus, and the ‘Akharas’, lead and initiate the bathing rituals, before the general population steps in.
Since these group of Sadhus reside in different parts of India, they all have to gather together and then they follow the festival or whatever the reason could be. There is also something very important process of participating in the festival which is called Peshwani. Basically Peshwani is a procession organized to show the official arrival of a group of Sadhus in a city. The same Peshwani was organized by Juna Akhada in Varanasi during Kumbh Mela 2013. I had heard a lot of Peshwanis but had never seen one but luckily this year I got an opportunity to see it. I made a video also which Peshwani of Juna Akhada in Varanasi on 2nd of March 2013 :