The Channar Lahala or Channar revolt, also called Maru Marakkal Samaram, refers to the fight from 1813 to 1859 of Nadar climber women in Travancore kingdom for the right to wear upper-body clothes to cover their breasts. This right was previously reserved for Nair women, who were higher-class Hindu women.

In Travancore, Cochin and Malabar, no female was allowed to cover their upper part of the body in front of Upper castes of Kerala until the 19th century. Under the support of Ayya Vaikundar, some communities fought for their right to wear upper clothes and the upper class resorted to attacking them in 1818. In 1819, the Rani of Travancore announced that the lower castes including the Nadar climber women have no right to wear upper clothes like most lower non-Brahmin castes of Kerala. However, the aristocratic Nadan women of the region were exempted from this restriction. Violence against Nadar climber women who revolted against this continued and reached its peak in 1858 across the kingdom, notably in southern taluks of Neyyattinkara and Neyyur.

On 26 July 1859, under pressure from the Madras Governor, the king of Travancore issued a proclamation announcing the right of Nadar climber women to wear upper clothes but on condition that they should not imitate the style of clothing worn by upper class women. Though the proclamation did not quell the tension immediately, it gradually subsided as the social and economical status of Nadar climbers progressed in subsequent decades with significant support from missionaries and Ayya Vaikundar.

Though the Nadar Christians improved their status with the aid of Christian missionaries, the outcome of the conversion was not according to the point of view of the missionaries. The Christian Nadar climber women, along with the Hindu Nadar climber women, wore the upper jacket in the manner of upper-class women and also their Tamil counterparts, in order to improve their social status. In turn they were discriminated and even abused by upper class men. One of the Nadan families of Agastheeswaram, instead of supporting their depressed counterparts, supported the upper class men and claimed that only their women had the right to wear an upper cloth.

In 1858, fresh violence broke out in several places in Travancore and the governor of Madras presidency, Charles Trevelyan, pressured the Travancore king. On 26 July 1859, the king issued a proclamation leading to the restoration of equal rights to wear upper cloth to all Kerala Nadar climber women.