Usage: 5 forms in 7 verses
Form Translated As     In Verse(s)
καταρχών who rules LXX.Nah.1.12
κατήρξαν they ruled LXX.Neh.9.28
κατάρχεισ you rule LXX.Num.16.13
κατάρξει he shall rule LXX.Zech.9.10
rule LXX.Zech.6.13
shall rule LXX.1Sam.9.17
κατάρξαι to rule LXX.Joel.2.17

Liddell-Scott-Jones

κατάρχω (katarchō) to rule G:V

κατάρχω-ω,

make beginning of a thing, c.genitive, τίνες κατῆρξαν.. μάχης; [κατάρχωειν">Refs 4th c.BC+] lead the way, [Refs 6th c.BC+]; τὸ κατάρχωον αἰσθήσεως, τῆς κινήσεως, the source of perception, of motion, [Refs 2nd c.AD+], begin a thing, [Refs 6th c.BC+]: with participle, begin doing, [Refs 5th c.BC+]

__2 θανόντα δεσπόταν γόοις κατάρξω I will lead the dirge over.., [Refs 5th c.BC+]
__II middle, begin, like active, with genitive, [κατάρχωεται [prev\. author] “Ph.” 540; τοῖς κατηργμένοις τῆς πορείας Plato Philosophus [{5-6th c.BC}] “Phaedrus” 256d; κ. τῆς προσβολῆς 2nd c.BC: Polybius Historicus 2.67.1; τοῦ λόγου Plutarchus Biographus et Philosophus [{1-2nd c.AD}] 2.151e ">Refs 6th c.BC+]: with accusative, κ. νόμον, στεναγμόν, [κατάρχωεται μέλος">Refs 5th c.BC+] is beginning, [Refs 2nd c.AD+].
__II.2 in religious sense, begin the sacrificial ceremonies, once in [Refs 8th c.BC+] began [the sacrifice] with the washing of hands and sprinkling the barley on the victim's head, [κατάρχωομαι μέν, σφάγια δ᾽ ἄλλοισιν μέλει">Refs 8th c.BC+] I begin the rite, but leave the slaughter of the victim to others, [κατάρχωεσθαι τοῦ τράγου">Refs 5th c.BC+] make a beginning of the victim, i. e. consecrate him for sacrifice by cutting off the hair of his forehead, [κατάρχωοντο 5th c.BC: Herodotus Historicus 2.45 ">Refs 5th c.BC+]; πῶς δ᾽ αὖ κατάρξῃ θυμάτω; [Refs 5th c.BC+]: metaphorically, [Refs 1st c.AD+] —so later in active, [Refs 3rd c.AD+]
__II.2.b sacrifice, slay, ξίφει, φασγάνῳ κ., [Refs 5th c.BC+] — passive, (i.e. τῇ θεᾷ) σὸν κατῆρκται σῶμα hath been devoted, [Refs]
__III active, rule, govern, with genitive, [Refs 4th c.AD+]
__IV κατάρξω ὑμᾶς ἐν σκορπίοις will chastise you.., [LXX]

LSJ Scripture Refs: LXX.1Kgs.12.24