Roman cavalry of the Republican period specialised in the shock charge, followed by close melee combat. Examples include the Battle of Sentinum (295 BC), in which the cavalry played a crucial role in the Romans' crushing victory over an enormous combined army of Samnites and Gauls. On the left wing, the Romans twice drove back the more numerous and highly rated Gallic cavalry with spirited frontal charges, but pursued too far and became entangled in a melee with the enemy infantry. This gave the Gauls the opportunity to unleash on the Roman cavalry their chariot forces, whose unfamiliar deep rumbling noise panicked the Roman horses and resulted in a chaotic Roman flight. However, on the right, the Roman cavalry routed the Samnite infantry with a devastating charge on their flank. At Heraclea (280 BC), the Roman cavalry dismayed the enemy leader king Pyrrhus by gaining the advantage in a bitterly contested melee against his Thessalian professional cavalry, then regarded as the finest in the world, and were only driven back when Pyrrhus deployed his elephants, which panicked the Roman horses. At Telamon (225 BC), the Roman cavalry hotly contested a strategic hill on the flank of the battlefield with more numerous Gallic cavalry. In what developed as a separate cavalry battle before the main infantry engagement began, the Gauls were eventually driven off the hill by repeated Roman charges, enabling the Roman horse to launch a decisive flank attack on the Gallic foot. At the Battle of Clastidium, the Roman cavalry under Marcellus achieved a unique victory in overwhelming a larger force of Gallic horse and foot, without any aid of their infantry. On the eve of the Second Punic War, therefore, Roman cavalry was a prestigious and much feared force.