Who is 10th Legion from The Conquest of Gaul and what is their importance?

The 10th Legion is without doubt Caesar's favorite. During his address to the council of centurions in the campaign against Ariovistus at Besançon, he tells the men of the 10th that he will use them as his bodyguard if the rest of the army does not follow him. Over the course of the British invasion, the 10th Legion is the first ashore at every landing.