"chronicle of events year-by-year," 1560s, from Latin annales libri "chronicles, yearlies," literally "yearly books," plural of noun use of annalis "pertaining to a year," from annus "year" (see annual (adj.)). In the early Roman republic, the Pontifex Maximus each year would record public events on tablets called Annales Maximi, hence Latin historical works were called annales.
word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.
Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.
<a href="https://www.etymonline.com/word/annalist">Etymology of annalist by etymonline</a>
Harper, D. (n.d.). Etymology of annalist. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/annalist