6.17.3–4

(February 1098)  Bohemond orders that each leader organize his (mounted) troops, and that they form five battle lines, with Bohemond's troops in reserve. The crusaders attack the Turkish advance guards, but are attacked in turn by the main Turkish army and start to retreat.  Bohemond urges his constable (and presumably the rest of his men) to remember that God is on their side, and charges like a lion.

6.17.3

per sē: CL would be ipse.

ōrdinātae sunt sex aciēs: the Franks were to fight in six separate units.

Quīnque vērō ex eīs: i.e., five of the six battle lines.  CL would be quinque eorum.

ūnus comminus percutiēbat alium: "one (Crusader) was striking another (an enemy) in hand-to-hand combat."

āerem: in CL the accusative singular is usually aera (a Greek acc.), but aerem does also appear. The motif is familiar from Herodotus (7.226) and elsewhere.  

maxima virtūs illōrum quae erat retrō: the bulk of the Turkish army, which had been held back in reserve.

6.17.4

suō conostābilī: “to his constable"; the medieval constable was the second-in-command.

Robertō fīliō Girardī: Robert Fitz-Gerard. He was Count of Buonalbergo and cousin of Bohemond.

quam citius: “as quickly as possible”; CL would use quam + superl.

estō: 2nd fut. imperat. > sum; a more urgent way of giving orders than the present imperative (CL).

in adiūtōrium: “for (the purpose of providing)”; ML often uses in + acc. to express purpose.

nōn est: CL would use a present subjunctive in primary sequence.

Fuit itaque ille: i.e., Bohemond.

linguae vēxillī: his banner had "points" (see media); the point is that Bohemond came very close to the Turks.