September 16, 2017: Indira Ekadasi
September 17, 2017: Vyatipata Mahalayam, Kanya Sankranthi, Pradosha Vratam
September 18, 2017: Kaliyugadi, Gajachhaya Parvam, Vishasastrahata Mahalayam, Maasa Sivarati
Vamana, the dwarf priest is considered as an incarnation of Lord Vishnu. King Bali is the grandson of King Prahlada. He is a mighty and valorous asura (rakshaha/demon). Having had conquered all lands on earth, he became mightier than ever. Having conquered Earth, his sight is on the next two lokas and this caused panic and fear in the minds of Lord Indra and other demingods. With not much to do by themselves, Lord Indra and others went to Lord Vishnu and appraised him of the situation.
Lord Vishnu takes birth in the form of Vamana in Kashyapa and Aditi, a Brahmin family. The birth of Vamana was on Shukla Paksha of Bhadrapad month in the Shravan Nakshatra. This auspicious day is celebrated as Vaman Jayanthi.
Back to the story, Vamana is a quick learner and gets good education par his age. He turns into a dwarf priest after undergoing the sacred thread ceremony.
With a belt made of munja straw, an upper garment of deerskin and a sacred thread and carrying in His hands a danda, an umbrella and a water pot (kamandalu), he appears before King Bali and seeks alms. The mighty Bali, happy with the appearance and knowledge of Vamana, asks Vamana as to what he wants. Vamana says he wants three feet of space. Bali is quick and grants the same.
The dwarf Vamana gradually transforms into a giant form, put one feet on Earth, the other on Heaven and asks Bali as to where the space for the third feet is located. Vamana puts his feet on the head of Bali and crushes him to the underground (Paatala Lokam). With this, the demigods gets saved.