over 40,000 men was too formidable for Hannibal to engage openly, and so the two played an unproductive game of cat and mouse in Bruttium; meanwhile, Marcus Livius, despite the added bulwark of two of the many Roman armies scattered across Italy, yielded cautiously to Hasdrubal, and allowed him to push beyond the Metaurus as far south as the town of Sena, today Senigallia. Prelude It was not until Hasdrubal sent messengers to Hannibal that decisive measures were finally taken. Hasdrubal wished to meet with his brother in southern Umbria. Hasdrubal's messengers were captured, and his plans fell into the hands of the consul Claudius Nero. Recognizing the urgency of the situation and the enormous threat that a merging of the Carthaginian brothers' armies would present to Rome, Nero decided to circumvent the authority of the Senate, also advising them to organize levies for their own protection. Leaving his camp under the command of his legate Quintus Catius, he then marched quickly to the North with 7,000 selected men, 1,000 of whom were cavalry, in order to join up with Marcus Livius. Horsemen were sent forward along the line of march with orders for country people to prepare supplies for soldiers, who took only weapons from the camp. Nero's troops were joined by both young and veteran volunteers during the march. Claudius Nero quickly reached Marcus Livius, who was camped at Sena along with the praetor Porcius Licinius. Hasdrubal was camped approximately a half-mile to the north. Because Claudius Nero had conveniently arrived at night, his presence was not detected until the next day, when the Romans drew themselves up for battle. Hasdrubal drew his army up as well, but upon closer observation of the forces assembled before him, noticed that Marcus Livius' army seemed to have grown considerably over the course of the night, and that he had a much larger contingent of cavalry. Hasdrubal remembered hearing a second trumpet in the Roman camp heralding the arrival of an important figure the night before—a sound with which he had become familiar during his entanglements with the Romans in Hispania—and correctly concluded that he was now facing two Roman armies. Fearing defeat, he retreated from the field. The rest of the day passed without event. When nightfall came, Hasdrubal quietly led his army out of his camp with the intent of retreating into Gaul, where he could safely establish communications