The six ages of history, with each age (Latin: aetas) lasting approximately 1,000 years, were widely believed and in use throughout the Middle Ages, and until the Enlightenment, the writing of history was mostly the filling out of all or some part of this outline.
Dating the First Age
' According to this dating, the First Age began about 4,312 years before the rising of the Sun, making the entire Age some 4,902 years long. This calculation is backed up by a further comment from other drafts of the Appendices: 'The First Age was the longest.
A period of 3,441 years from the defeat of Morgoth, to the first defeat of Sauron.
In the notes to The Annals of Aman, Tolkien stated a single Valian year lasts 1,000 Valian days, defined as the duration of a complete flowering of the Two Trees of Valinor.
The long 'years' of the Elves
The main units of time used by the Elves; one yén was equivalent to 144 years.
According to that definition, the First Age 'proper' followed the Years of the Trees and lasted only c. 600 years until the beginning of the Second Age.
First Age lasted for 450 Years of the Trees plus 590 Years of the Sun, thus numbering in total 4 902 Years of the Sun, since each Valian Year was equal to 9.582 coranari (solar years).
The series is set during the Second Age of Middle-earth. That alone would seem to rule out any possibility of Gandalf appearing in The Rings of Power. According to this history, Gandalf and his fellow wizards don't appear in Middle-earth until the Third Age, well after the events being chronicled in The Rings of Power.
As soon as the Mystics realize the Stranger isn't Sauron, they label him an "Istar." With this label, and several other hints throughout the episode and the season, The Rings of Power has all but confirmed that the Stranger is everyone's favorite wizard: Gandalf the Grey.
Middle age, commencing at about 40 years, is followed by old age at about 60 years.
It lasted for 3021 years, only ending after the defeat of Sauron had finally and utterly been achieved by destroying his Ruling Ring. With the One Ring gone, the power of three rings waned and the realms that had been preserved by them began to fade.
The Third Age began after the first overthrow of Sauron by the Last Alliance, and was marked by Isildur's planting of the White Tree in Minas Anor. It ended more than three thousand years later with the destruction of the One Ring, the final end of Sauron, and the passing of the Ring-bearers over the Sea.
Frodo Baggins was a hobbit of the Third Age, the most famous of all Hobbits in the histories for his leading role in the Quest of the Ring. During this epic quest, he bore the One Ring to Mount Doom and there destroyed it, giving him renown like no other Halfling throughout Middle-earth.
Both Tom and Treebeard were referred to as the oldest living creatures of Arda, though it is not clear which of the two is the oldest. However, according to Tolkien's letters, it is implied that Bombadil was the oldest living being in Middle-earth.
History is divided into five different ages: Prehistory, Ancient History, the Middle Ages, the Modern Age and the Contemporary Age. PREHISTORY extended from the time the first human beings appeared until the invention of writing. ANCIENT HISTORY extended from the invention of writing until the fall of the Roman Empire.
The ages of his characters differ wildly; Gollum is almost 600 years old, while Elrond, the elf, is several thousand years old, and Gandalf the Grey – and later the White – is immortal (for display reasons, both are thus not mentioned here).
Alarmed, Gandalf tells Bilbo that is foolish. Coming to his senses, Bilbo admits that the ring has been troubling him, and leaves it behind for Frodo as he departs for Rivendell. Over the next 17 years, Gandalf travels extensively, searching for answers on the ring.
He died at the age of 210, after 122 years as king. The graves of the hobbits Merry and Pippin (who had died in Gondor 58 years earlier) were set beside his. He was succeeded on the throne by his son, Eldarion.
We know that the storylines in The Rings of Power are set in the Second Age, which occur thousands of years before the events of The Lord of the Rings. We also know that when Galadriel finally returns to her birthplace of Valinor after the destruction of the One Ring, she is over 8,000 years old.
In short, Sauron is as old as creation itself, and was created before the physical world was established. He is one of the Maiar, primordial spirits who were created by Eru - the original essence and creator of the universe - to assist the Valar in shaping the physical world.
The History of the Fourth Age
During this period, the Shire became more important in the wider politics of Middle-earth. By the edict of King Elessar, Men were banned from its borders, but it remained nonethless a part of the North-kingdom.
Sauron was originally a Maia called Mairon, but he could take on a fair visage and call himself Annatar or Halbrand. He is not an elf or human, but an extremely powerful being and the main antagonist of J.R.R. Tolkien's The Lord of the Rings.
But, if we're speaking strictly of events inside the legendarium, then there's no mention of a Fifth Age. Of course, time goes on, so even if Tolkien didn't write it, logic tells us there'd probably be a Fifth Age, and more ages after that, until the Dagor Dagorath and the world is remade.