Radagast is, of course, a worthy wizard, a master of shapes and changes of hue; and he has much lore of herbs and beasts, and birds are especially his friends.
― Gandalf in The Fellowship of the Ring, The Council of Elrond

Radagast the Brown, also known as Aiwendil, was one of the Wizards sent to Middle-earth to contest the will of Sauron. Originally a Maia of Yavanna, he had a strong affinity for animals. He dwelt, for a time, at Rhosgobel on the western eaves of Mirkwood, near the Gladden Fields on the Great River.




History
The Maia Aiwendil was an Ainu who existed before Time, and one of the spirits who descended to Arda in order to serve the Valar. Aiwendil was a servant of the Valië Yavanna, the Queen of earth.

After the Valar discovered the primeval Elves at Cuiviénen, Aiwendil was sent there with several other Maiar to guard the Elves from the forces of Melkor. He was known there by the name Hrávandil. It is unclear how long he remained or if he accompanied the Eldar on the Great Journey.

After the defeat of Morgoth, the Valar grew concerned about the growing power of Sauron in Middle-earth. Manwë summoned a council of the Valar, and it was decided that they would send Maiar as emissaries to Middle-earth to aid the Free Peoples. Aulë chose Curumo (later Saruman), Oromë chose Alatar, and Manwë chose Olórin (later Gandalf). Yavanna subsequently begged Curumo to take Aiwendil with him, much to Curumos displeasure.

In c. T.A. 1000, the Maiar arrived upon the shores of Middle-earth, having the form of old Men, whom the peoples called Wizards. Curumo arrived first and alone, and Aiwendil arrived at the same time as Olórin. In Middle-earth he was known as Radagast, and he was robed in brown.



Mage of Rhosgobel by Jef Murray

Travels in Middle-earth
When the Wizards took their mission they roamed Middle-earth, but Radagast was never much of a traveller. There is not much to be told about his early journeys, but by the late Third Age he eventually settled down and dwelt, for a time at least, at Rhosgobel somewhere between the Carrock and the Old Forest Road. Situated on the western borders of Mirkwood, it can be assumed that the Wizard held watch against the Shadow of Dol Guldur that slowly engulfed the forest. It is likely that he became acquainted with the inhabitants of that region. Close to animals and birds, he was friends with the great eagles. Although the neighboring Beorn was unsociable, he used to see him from time to time, and he considered Radagast not bad for a Wizard.






In T.A. 2851, the White Council met once more and, after that, Saruman began to search the Gladden Fields for the One Ring. Radagast decided to aid his search with birds and beasts who acted as spies hoping that Sarumans actions would help watch and hinder Sauron. Radagast did this in good faith, knowing nothing of Sarumans real ambitions to keep the Ring for himself.

By the time of the War of the Ring Radagast did not dwell any more in Rhosgobel. In summer T.A. 3018 Saruman told Radagast that he was willing to help Gandalf, and sent the Brown Wizard to seek him out at once. Radagast did not know much of Eriador but sought for the Shire, knowing that he would find Gandalf nearby.

Indeed, on Midsummers Day, Radagast was sitting on the side of the Greenway with his horse near Bree when Gandalf found him on his way to the village. Radagast warned Gandalf that the Nazgûl were abroad, disguised as riders in black, and that they were seeking news of the Shire. He also gave him Sarumans invitation and agreed to help Gandalf by getting beasts and birds to send news to Orthanc. With that he rode away back towards Mirkwood.



Radagast in LOTR- War in the North

By sending Gandalf to Orthanc, Radagast unwittingly had him captured. Sarumans message proved to be a trap for Gandalf who was imprisoned in Orthanc, but still he did not believe that Radagast was also a part of Sarumans plans. Indeed, it was thanks to Radagast that Gandalf was able to escape from the pinnacle of Orthanc upon the wings of Gwaihir.

Radagasts actions during and after the rest of the War are not recorded. After the Council of Elrond, many scouts were sent out from Rivendell to many different locations. Some passed over the Misty Mountains and eventually came to Rhosgobel, but they found that Radagast was not there.




The Hobbit - An Unexpected Journey - Radagast


Other names
The name Aiwendil is Quenya for Lover of Birds. It is obviously derived from aiwë (a small bird) + -ndil (devoted to).

Another Quenya name was Hrávandil, used when he was sent to Cuiviénen with the other Guardians, which according to Carl Hostetter most likely means Wild beast friend, from hravan (wild beast) + -ndil (friend).

As one of the Wizards sent to Middle-earth, he was known as Radagast the Brown.