Iḷaiya Perumāḷ — 'the young lord' — is the affectionate Tamil title by which Śrī Lakṣmaṇa, younger brother of Śrī Rāma, is known in the Śrī Vaiṣṇava tradition. The title honours both his royal birth as a prince of Ayodhyā (Perumāḷ = 'the great lord / the one who is greatly revered') and his role as the quintessential younger companion (Iḷaiya = 'younger').
In Śrī Vaiṣṇava theology, Śrī Lakṣmaṇa is the supreme exemplar of śeṣatva — the condition of existing wholly as the instrument and servitor (śeṣa) of Bhagavān and His devotees. When Śrī Rāma was exiled, Lakṣmaṇa needed no instruction, no persuasion, and no deliberation; he spontaneously abandoned all royal comfort to follow his elder brother into the forest. This effortless, joyful, unconditional service is what Piḷḷai Lōkācāryar and Maṇavāḷa Māmunigaḷ cite as the very definition of ānukūlya-saṃkalpa — the will to do only what is pleasing to Bhagavān. Vibhīṣaṇa's surrender is cited as an example of prapatti; Lakṣmaṇa's service is cited as the example of śeṣatva at its most natural.
The Rāmāyaṇa presents several episodes that the sampradāya dwells on: Lakṣmaṇa's refusal to rest while Rāma was awake, his standing guard through the night, his lament at the apparent death of Rāma during the battle, and his role as the intermediary through whom Vibhīṣaṇa gained access to Rāma's protection. Āzhvārs and Ācāryapuruṣas frequently invoke Iḷaiya Perumāḷ as the model for the soul's relationship with Bhagavān — not the grand gesture of formal surrender alone, but the sustained, daily, joyful subordination of one's entire existence to the Lord.