Rúmil of Tirion invents a written alphabet
Event Type: Cultural/Social
Age: Time of the Trees
In this year  Rúmil, most renowned of the masters of the lore of speech, first devised letters and began recording in writing the tongues of the Eldar and their songs and wisdom.
Morgoth's Ring, HoME Vol 10, Part 2, The Annals of Aman
Rúmil of Tirion was the name of the loremaster who first achieved fitting signs for the recording of speech and song, some for graving upon metal or in stone, others for drawing with brush or with pen.
The Silmarillion, Quenta Silmarillion, Ch 6, Of Fëanor and the Unchaining of Melkor
The Tengwar were... ancient; for they had been developed by the Noldor, the kindred of the Eldar most skilled in such matters, long before their exile. The oldest Eldarin letters, the Tengwar of Rúmil, were not used in Middle-earth. The later letters, the Tengwar of Fëanor, were largely a new invention, though they owed something to the letters of Rúmil.
The Return of the King, LoTR Appendix E, Writing and Spelling: Writing
Elena Tiriel 14Mar08