Context: The centenary of the Sri Nankana Sahib massacre, which is popularly known as Saka Nankana Sahib, is being marked in an event there on February 21 this year. 
About Nankana Sahib

• Nankana Sahib is a city in Pakistan’s Punjab province, where Gurdwara Janam Asthan (also called Nankana Sahib Gurdwara) is located. 
• The shrine is built over the site where Guru Nanak, the founder of Sikhism, was believed to be born in 1469.
• The city was previously known as Talwandi.
• The Janam Asthan shrine was constructed by Maharaja Ranjit Singh, after he visited Nankana Sahib in 1818-19 while returning from the Battle of Multan.

Significance

• Gurudwara reform movement: Nankana Sahib, the birth place of first Sikh guru, Guru Nanak Dev, was also the site of the first big agitation by the SGPC to take back control of gurdwaras from mahants backed by the British.

Gurudwara reform movement

• The Shiromani Gurdwara Parbandhak Committee (SGPC) came to existence in November 1920, a month after Sikhs removed partial restrictions on Dalit rights inside Golden Temple in Amritsar.
• It started a gurdwara reform movement which was aimed at taking possession of historical Sikh Gurdwaras, which had turned into personal property of the priests, who were called mahants. 
• These mahants were also accused of running practices from gurdwaras which were not approved in Sikhism.

The Shiromani Gurdwara Parbandhak Committee 

• It is an organization in India responsible for the management of gurdwaras, Sikh places of worship in three states of Punjab, Haryana, and Himachal Pradesh and union territory of Chandigarh. 
• SGPC also administers Darbar Sahib in Amritsar.

The February massacre

• During British rule, the Gurdwara Janam Asthan was the site of a violent episode when in 1921, over 130 Akali Sikhs were killed after they were attacked by the Mahant of the shrine. 
• The  SGPC formed its own probe team and asked Mahatma Gandhi to be part of it. 
• Gandhi asked Sikh leaders to give support to the non-cooperation movement of the Congress party.
• The SGPC called a meeting on March 6, 1921 decided to support the non-cooperation movement being run by Mahatma Gandhi.
• The incident is regarded as one of the key milestones in the Gurdwara Reform Movement, which led to the passing of the Sikh Gurdwara Act in 1925 that ended the Mahant control of Gurdwaras.