Thousands of Shia militia members from all over Iraq rallied in a show of strength .
21 June : After the agreed desertion of 400 Iraqi soldiers , ISIL captured Iraq 's largest oil refinery in Baiji .
Thousands of Shia militia members from all over Iraq rallied in a show of strength .
21 June : After the agreed desertion of 400 Iraqi soldiers , ISIL captured Iraq 's largest oil refinery in Baiji .