Why in News? 

• March 23 is observed as Shaheed Diwas or Martyr’s Day. 

About Shaheed Diwas: 

• This day marks the execution of three revolutionaries in 1931 – Bhagat Singh, Sukhdev Thapar, and Rajguru – for the assassination of British police officer John Saunders. 
• Bhagat Singh: Founded the Naujawan Bharat Sabha (Youth Society of India). 
• Sukhdev Thapar: 
  • Member of HSRA (Hindustan Socialist Republican Association). 
  • Organized revolutionary cells in Northern India. 
•  Rajguru: Shivaram Hari Rajguru was a key member of HSRA.