Caesar 54BC Planning





Following the return of the Roman forces to Gaul from the abortive reconnaissance the previous year, Caesar returned to Italy for the winter.

However, before leaving Gaul, he gave instructions for the repair of existing ships and construction of additional ships during the winter by Legionary and Marine craftsmen to support a second invasion in 54BC.

The additional transports were to be made to an altered design, based on lessons learned during the aborted reconnaissance and which also incorporated features from Veneti ships. The new ships were of shallower draught than traditional Roman transports, wider, with lower freeboard and included the provision of oars at the bow and stern in addition to sail power. All designed to allow the transports to draw closer inshore, allow faster, and safer disembarkation by legionaries onto an open beach.

It was normal for Marines/ships crews to spend winter refurbishing their ships, and had sufficient skills to do this and also construct new ships. So by the time campaigning season for 54BC arrived, about 800 transports plus 28 warships were said to be available for operations.

(Some sources consider this an excessive number considering that the previous year only 80 transports were needed to carry 2 legions so on the same basis 5 legions would have needed 200 ships. Allowing another 100 ships to cover the increased supplies needed to guarantee a longer stay without risking supply shortages, plus loading additional cavalry and auxiliaries would give a more reasonable number of 400 transports plus warships. Whatever the actual number the fleet would have been larger than anything previously seen in British waters.)

Some sources consider up to 150 men could have been loaded per ship for a lightly loaded expedition. (Say the previous year). While for a fully equipped long stay expedition 60 to 70 men  per ship would have been reasonable. With a full strength century comprising 80 men it seems probable that an average century was loaded one to a ship, with any excess carrying capacity made up with additional supplies. This would have simplified unit cohesion on landing no matter what chaos resulted from a landing disrupted by opposing forces or weather.

Another way of counting ship loading was with Cavalry being loaded 10 to 15 horses plus handlers per ship.


So the size of the fleet required to carry the invasion force could comprise.

For each legion of 9 cohorts each of 6 centuries, plus the double size first cohort - total 56 ships.
Four legions  - total 256 ships.
Add 2000 Cavalry at 10/15 per ship - say 150 to 200 ships.
Add an unknown number of Auxiliaries.
Then add an unknown number of ships for logistics, supplies, mules, etc.

We come to a minimum number of ships of 500, with 800 also being a good number. A reasonable number of transports needed would comprise anything between these two figures.


- 54BC Planning
- 54BC Objectives
- 54BC Timing & Crossing
- 54BC Military Units 
- 54BC Landing
- 54BC Land Operations
- 54BC Consequences
This page last edited - 22 December, 2012.

Copyright Ian M King, except where otherwise indicated.