Story of Rani Veeravati
Veeravati was the only sister to her seven brothers. After her marriage she came back to her maternal home to celebrate the festival of Karva Chauth; being her first Karva Chauth, she kept a strict fast that day. In evening she started to feel severe hunger and thirst, upon seeing this, her brothers decided to help her and concocted a plan to create a false moon by tying a mirror at the ‘pipal' tree far away from their home.
They convinced her that the moon has risen, despite being told by her sister-in-laws about the plan she showed trust upon her brothers and broke her fast.
The moment she started eating, a word from near-by state came announcing that the King (her husband) has died. Upon listening to this she wept the whole night, Goddess appeared on seeing her weeps and told her about the reality how she had been ditched by her brothers.
The Goddess then blessed her that if Veeravati kept another Karva Chauth fast with full devotion her husband would be revived. Queen Veeravati did the entire puja with deep devotion; hence Lord Yama had to return her back her husband. Therefore since that day, every year married Hindu women keep a fast on this day and pray with full devotion for their husbands long-life, health and success.