Across

4 Fight
8 Movable towers
12 A military group of 6 centuries of men
15 Oar
16 A beak or the prow of a ship
17 Ancient Roman military company of about 80 soldiers
18 Soldier
21 Additional military troops
22 Ditch dug around a camp
24 War
25 Ten cohorts of soldiers
26 Sword
27 Lesser goddess of war

Down

1 Heavy-duty crossbow
2 The personification of Discord
3 The leader of the Roman fleet
4 Administration building of an ancient Roman fort
5 Rampart
6 House in an ancient Roman fort for the unit's commander
7 Smallest ancient Roman military grouping, about 8 men
9 A high-powered crossbow
10 Army
11 High-powered ancient Roman ship with three sets of oars
13 Ancient Roman god of war
14 A battering-ram
17 Fortified ancient Roman camp
19 A boat's sail
20 Goddess of trickery
21 One of the three Furies, important in the Aeneid
23 A roof under which besiegers could hide to protect themselves from objects thrown down on them