ἐντεῦθεν
μέγα γὰρ τὸ τῆς θαλάσσης κράτος → great is the power of the country that controls the sea, control of the sea is a great thing, the dominion of the sea is a great matter, the rule of the sea is a great matter, the rule of the sea is indeed a great matter, control of the sea is a paramount advantage
English (LSJ)
Ion. ἐνθεῦτεν, Adv., (related to ἔνθεν, as ἐνταῦθα to ἔνθα): I of Place, hence or thence, Od.19.568, Hdt.1.2, al., A.Pr. 836, Pers.488, Th.8.42, etc.; τὸ γένος ἐ. ποθεν ἐκ Χίου Pl.Euthd.271c; τἀντεῦθεν matters there, i.e. in the house, S.El.1339; ἐ. καὶ ἐ. LXX Nu.22.24, Ev.Jo.19.18; ἐ. κἀκεῖθεν Sch.D.T.p.29H.; ἐντεῦθεν εἰς τυχόν 'go to Jericho', Men.Pk.184. II of Time, henceforth, thereupon, S.El.728, Ph.384 (lyr., dub. l.), etc.; also τὸ ἐ. Hdt.1.9, 27, al., Pl.Tht.198b; Att. also τοὐντεῦθεν E.Med.792, al.; τἀντεῦθεν A.Eu. 60; τὸ ἐ. ἐπὶ τούτοις Ael.NA8.17. III causal, thence, from that source, τὸν βίον ἐ. ἐποιοῦντο Th.1.5; ἐ. αἱ μάχαι Arist.EN1131a23; ἐ. ποθεν Id.Pol.1286b15; therefore, in consequence, E.Andr.949, Pl.Cra. 399c.—Att. strengthd. ἐντευθενί [ῑ], Ar.Av.10, Lys.92, etc.; cf. ἐνμεντευθενί.