Tolkien's final First Age timeline

[Arvegil145]

Before I make my point about Ents, it occurred to me that maybe you could add certain dates before the First Age (i.e. before VY 850/1) -

1) the creation of the Two Trees (VY 1/1)

2) the creation of the Dwarves by Aule, and other still applicable events (https://tolkiengateway.net/wiki/Year_of_the_Trees_1000 )



As to the Ents - Elves were clearly in contact with the Ents at some point; when exactly? Who knows. But it seems that they inspired Ents towards language.

There's this quote from Letter 131:

Even some whole inventions like the remarkable Ents, oldest of living rational creatures, Shepherds of the Trees, are omitted.

However, given the numerous developments in the legendarium since that letter (c. 1951), I can hardly take that letter as the 'latest'.

Especially given these three quotes in conjunction:

1)

The fëar of the Elves and Men (and Dwarves via Aulë, Ents via Yavanna) were intrusions into Eä from outside. As the Valar were sent into Eä.

- NoME, 'Primal Impulse', Text A, p. 290; indicating that Ents are some kind of equivalent to the Dwarves

+

2)

Durin I, eldest of the Fathers, 'awoke' far back in the First Age (it is supposed, soon after the awakening of Men)...

- PoME, 'Last Writings', p. 383

+

3)

Learn now the lore of Living Creatures! First name the four, the free peoples: Eldest of all, the elf-children; Dwarf the delver, dark are his houses; Ent the earthborn, old as mountains; Man the mortal, master of horses

- LOTR one-volume edition, 'Book Three', 'Treebeard', p. 464



How do you make sense of this mess?