What is the story behind Lord Rudra (Shiva) holding the skull of Indra?

Question

I read the extract as shown in the image below from Vayuviya Samhita Chapter 14 of Shiva Purana:

In the verse # 9 (the highlighted one), it is said that:

He (Lord Rudra) is brilliant holding the skulls of asura Jalandhara, Brahma and Indra, his tawny hair, mustache and beard are drenched in the surging waves of Ganga.

This line is said in the praise of Lord Rudra (popularly known as Lord Shiva). I am aware that Jalandhara was a demon killed by him. Lord Brahma's one head was also cut by Lord Rudra/Shiva but I don't know of any incident where Indra's head was being cut by Lord Rudra/Shiva. Do we have any scriptures that store some story behind this?

Answer 1

This skull could be probably skull of a previous Indra. Rudra at Prakrta Pralaya (dissolution after death of Creator Brahma) burns entire Universe to ashes and wears skulls of Devas as Ornaments. So, there could be a chance that this skull belongs to some previous Indra.

Chapter 46, Uttara Bhaga of Kurma Purana mentions Prakrta Pralaya in detail and says Rudra wears skulls of all Gods as ornaments.

स दग्ध्वा सकलं विश्वमस्त्र ब्रह्मशिरो महत्।
देवतानां शरीरेषु क्षिपत्यखिलदाहकम्॥६॥

Reducing to ashes the entire universe, Mahesvara then shoots a terrific weapon called Brahmasiras, which can even burn the bodies of the gods.

दग्धेष्वशेषदेवेषु देवी गिरिवरात्मजा।
एषा सा साक्षिणी शम्भोस्तिष्ठते वैदिकी श्रुतिः॥७॥

When all the gods were reduced to ashes, Parvati, the excellent daughter of Himalaya, stands by Siva as the only witness of his performance. This has been ordained by the Vedic Srutis.

शिरं कपालैर्देवानां कृतस्रग्वरभूषणः।
आदित्यचन्द्रादिगणैः पूरयन्व्योममण्डलम्॥८॥

Lord Siva, wears a garland of skulls of the gods, as an ornament. He fills the sky with the multitudes of suns and the moons.

Answer 2

It is from the time when Rudra killed Vishnu, Indra and many others. This is given in Chapter 100 - Destruction of Daksha's Sacrifice, of the Shaiva Linga Purana:

In the great sacrifice of Daksa, Lord Rudra burned Devas along with Visnu and sages. (2) His Gana named Bhadra was sent by the lord Paramesthin (3)

He (Veerabhadra/Rudra) cut off the head of lord Indra ... ... Without any difficulty he killed thirty three Devas thus. Sportingly he killed three thousand three hundred and thirty three Devas along with the three leading Devas. He killed the leading sages too. This lord killed those Devas who stood in readiness for fighting. Lord Rudra hit them with his fist, swords, arrows and other things. Then Visnu of great splendour and intensified strength lifted up his discus, and fought with Rudra ... ... Through contact with the tips of the bits of the bow he (Rudra) cut off the head of the lord (Vishnu). His head that was cut off fell quickly into the nether worlds wafted by the wind originating from the vital breaths of the Pinaka-bearing lord. (18-32)

But everything went well in the end:

On being requested by lord Brahma, the great lord of all the worlds the bestower of everything gave back their own respective bodies to those who were killed. He gave back the head to Indra, to Visnu, to Daksa and to the leading sages and others. He gave back the tip of the nose to the goddess Sarasvati and to the mother of Devas. He gave back life to all those who were destroyed. (41-46)