In Arabic, Arbaeen means the 40th day and 20th of Safar, which is 40 days after the martyrdom of Imam Hussein (PBUH) on the Day of Ashura, which is called Arbaeen al-Husseini or simply Arbaeen.
Procession of Arbaeen is a great march of Shia in Iraq from different parts of the country towards Karbala on the occasion of Arbaeen to pay a visit to the shrine of Imam Hussein and perform ziyarat al-Arbaeen.
Millions of people participate in this annual procession. Many people from other countries travel to attend the event as well.