In every Vaishnavite temple in South India, one hears beautiful poetry in Tamil in praise of Vishnu . One well-known song is

This song and many others were written by Azhwars.
Azhwar means one who is "immersed" in the experience of
God. They really, deeply immersed themselves in their devotion and bhakti towards the Lord Sriman Narayanan. Tradition reckons 12 Azhwars. All these Azhwars are one of the Amsams of Lord Vishnu, ,namely, the weapons, the Vanamaali, the GarudA, et al. There is a view that even the great Rishis are no match to the greatness of the Azhwars because the Rishis got their 'jnAnam' ( wisdom) as a result of their own actions of 'spiritual merit' ( Punyam) whereas the wisdom of the Alwars was the direct result of the Lord's divine grace and therefore called ' Divyam'. It is because of this that the works of Azhwars are called ' Divya Prabandham'.
Out of these 12 Azhwars one was a woman and two were kings. The first three Azhwars,viz., Poigai Azhwar, Boothath Azhwar and Pei Azhwar were called as "Mudhal Azhwars" as they lived during the same period and were born in the same year, same month and contiguous stars (Thiruvonam, Avittam and Sadhayam).
The period of the Azhwars based on Indian Historians range from 500 A.D for Poigai Aazhvaar, Bhoothatthaazvaar, Peyaazhvaar and Thirumazhisai aazhvaar ; 550 A.D. for Nammaazhvaar and Madhurakavi aazhvaar ; 600 A.D. for Kulasekaraazhvaar and Periaazhvaar ; 650 A.D. for Sri Aandaal ; 700 A.D. for Thoddaradippodi aazhwarand ThiruppaaNaazhvaar and 750 A.D. for Thirumangai aazhvaar
There are about 3800 compositions (known as Paasurams) of the 12 Azhwars available now. The well known
30 songs of Thiruppaavai are among the 173 composed by Andal, probably
the first female composer of the world. The style of the 1360 compositions
of Thirumangai mannan (Thirumangai Azhwar) is believed to be specially suited for music and
dance. Ariakkudi Ramanuja Iyengar is responsible for re-introducing Thiruppaavai
into Classical Music of South India. Late Shri V.V. Sadagopan, Musicologist,
Professor of Carnatic Music, Delhi University, dedicated his life to bringing
back many more Azhvaar Pasurams into the Musical realm.
By 850 AD, the compositions of the Azhvars had become almost totally
extinct in the Tamil Country. It is believed that Sriman Naathamuni heard some devotees visiting his home town of VeeranaaraayaNapuram (present day Kaattu mannaarkudi near Mayilaadurthurai or Mayavaram) singing 11 Tamil songs starting with "aaraa amudhE adiyEn udalam" and ending with
"... kurugoor sadagOpan
kuzhalil maliyach sonna Or
aayiratthuL ippatthum,
mazhalai theera vallaar kaamar
maanEy nOkkiyarkE."
(NammazhwAr's Thiruvaaymozhi 5.8.1 - 5.8.11)
Sriman Naathamuni was greatly excited and enchanted with the exquisite beauty of the poems. He approached the devotees and enquired about its origin. The ending of the 11 poems, "aayiratthuL ippatthu,"(means this ten of the thousand) suggested that there are many more such poems (may be thousand?). This possibility intrigued Sriman Naathamuni.
Unfortunately, the devotees were unaware of any other poems besides the eleven they had just finished reciting. However, they suggested to Sriman Naathamuni that he may try enquiring in the town of Thiruk kurugoor (AzhwAr thiru nagari) near Thirunelveli. So he set out to travel from Kaattumannarkudi to Thiruk kurugoor, a long journey indeed in his time. There he found one Paraangusa daasar. From him, Sriman Naathamuni learnt 11 more paasurams called 'kanninuN sirutthaambu'. These were composed by Madhurakavi AzhwAr and all 11 paasurams are in praise of kurugoor SadagOpan (Nammazhwar). Sriman Naathamuni was excited to have doubled his collection. But this only enhanced his desire to seek out the more than 1,000, promised in the first set of paasurams he fell in love with at his home town.
Paraangusa daasar suggested that he repeatedly recite this great kaNNinuN sirutthaambu (sung in praise of Sri Sadagopan- NammazhwAr) in the hope of pleasing the Lord.

Sriman Naathamuni took his advice sincerely and recited it about 12,000 times! It is said that NammAzhwAr was impressed with Sriman Naathamuni's persistence and appeared before him. NammazhwAr was so impressed that he revealed to Sriman Naathamuni not just the 1102 paasurams of his own "Thiruvaay mozhi", but also all the rest of the paasurams composed by the other eleven AzhwArs. From this, we may deduce that it is Sriman Naathamuni, who gathered the Tamil treatise (these 4000 poems) praising Lord Vishnu composed by the twelve AzhwArs. Sriman Naadhamuni called this collection of paasurams or prabhandams 'Naalaayira Divya Prabhandam' or 'Draavida Vedham'.
He set them to music
as they were originally sung by the Azhvars. He taught them to his nephews
Melagaththaazhvaan and Keezhagaththaazhvaan and also to his son Isvaramuni and grand son Aalavandhaar. Later Aalavandhaar taught those to his disciples Peria Nambi, Peria Thirumalai Nambi, Thirumalai Aandaan etc..
They in turn taught them to Sri Ramanujacharya (1017-1137 AD), who publicised them among his followers.
There is much debate about the exact historical dates for the twelve AzhwArs. It is believed by devotees that most of the AzhwArs lived prior to kali yuga, i.e. at least 3000 years ago. Historians place the Aazhvaars in the range of 5th to 9th century. In any case, we can be sure that the AzhwArs lived much before Sriman Naathamuni (826 A.D.) since it was only during his time that the AzhwAr pAsurams had become unknown.
Out of the 12 Azhwars four were from Thondai Naadu, four from Pandiya Naadu, three from Chola Naadu and one from Malai Naadu. Andal who is also called as "Soodikkodutha Sudar Kodi" is said to be the daughter (brought up) of Peri Azhwar has created "Thiruppavai" in which she considers Lord Vishnu as her husband. She is the only lady Azhwar.
The Azhwars came from all walks of life and all strata of society. In the Tamil-speaking region of South
India, these saints revitalized the Indian religious milieu, sparking a renewal of devotional worship throughout the subcontinent. Traveling from place to place, from temple to temple, from holy site to holy site, they composed exceedingly beautiful poetry to their Divine Beloved, Vishnu, as an
expression of their love for Him. Anyone can see why their poetry was so attractive; at once both impassioned and philosophical, their words cut across all barriers of caste and class, attracting all to their faith. In doing so, they sculpted a new religious heritage of intensely emotional
bhakti, or love of the Divine, whose impact is still felt today in the Indian religious life.
 Poigai Azhwar
Birth Place Thiruvekoo (Kancheepuram)
Year/Month/Star Chiththathri/Aipasi/Thiruvoonam
Amsam Thiruchangu (Panchajanya)
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 Boothath Azhwar
Birth Place Mamallapuram
Year/Month/Star Chiththathri/Aipasi/Avittam
Amsam Gadhaayudham
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 Pei Azhwar
Birth Place Mylapore(Chennai)
Year/Month/Star Chiththathri/Aipasi/Sadayam
Amsam Nandhagam(Sword)
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 Thirumezhisai Azhwar
Birth Place Thirumezhisai (Chennai)
Year/Month/Star Chiththathri/Thai/Maham
Amsam Chakra
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 Namm Azhwar
Birth Place Tirukurugoor (Azhwar Tirunagari)
Year/Month/Star Pramaashi/Vaikasi/Visakam
Amsam Vishwaksena
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 Peri Azhwar
Birth Place Srivilliputhur
Year/Month/Star Krodhana/Aani/Swathi
Amsam Garuda
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 Andal
Birth Place Srivilliputhur
Year/Month/Star Nalla/Aadi/Pooram
Amsam Bhoodevi
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 Kulasekhara Azhwar
Birth Place Thiruvanjikkallam
Year/Month/Star Paraabhava/Maasi/Punarpoosam
Amsam Kowsthubam
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 Madhurakavi
Birth Place Thirukollur (Azhwar Tirunagari)
Year/Month/Star Eeswara/Chithirai/Chithirai
Amsam Ganamsam
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 Tondar-adi-podi Azhwar
Birth Place Thirumandangudi
Year/Month/Star Prabhava/Markazhi/Keetai
Amsam Sri Vaijayanthi Vanamaalai
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 Tiruppaan Azhwar
Birth Place Uraiyur (Trichy)
Year/Month/Star Purdhurmathi/Kathigai/Rohini
Amsam Sri Vatsam
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 Tirumangai Azhwar
Birth Place Thirukurayalur (Thiruvali)
Year/Month/Star Nalla/Karthigai/Krithigai
Amsam Saarangam (Bow)
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