Question: Who introduced a system of musical notation used in the region the Romans aimed to re-bolster influence in after the Second Punic war in the 14th century?

Knowledge 1: Hellenistic period
Once the Second Punic War had been resolved, and the Romans had begun to regather their strength, they looked to re-assert their influence in the Balkans, and to curb the expansion of Philip. A pretext for war was provided by Philip's refusal to end his war with Attalid Pergamum, and Rhodes, both Roman allies. The Romans, also allied with the Aetolian League of Greek city-states (which resented Philip's power), thus declared war on Macedon in 200 BC, starting the Second Macedonian War. This ended with a decisive Roman victory at the Battle of Cynoscephalae (197 BC). Like most Roman peace treaties of the period, the resultant 'Peace of Flaminius' was designed utterly to crush the power of the defeated party; a massive indemnity was levied, Philip's fleet was surrendered to Rome, and Macedon was effectively returned to its ancient boundaries, losing influence over the city-states of southern Greece, and land in Thrace and Asia Minor. The result was the end of Macedon as a major power in the Mediterranean. [SEP] Knowledge 2: Late Middle Ages
The main representatives of the new style, often referred to as ars nova as opposed to the ars antiqua, were the composers Philippe de Vitry and Guillaume de Machaut. In Italy, where the Provençal troubadours had also found refuge, the corresponding period goes under the name of trecento, and the leading composers were Giovanni da Cascia, Jacopo da Bologna and Francesco Landini. Prominent reformer of Orthodox Church music from the first half of 14th century was John Kukuzelis; he also introduced a system of notation widely used in the Balkans in the following centuries.
Knowledge 1: Hellenistic period
Once the Second Punic War had been resolved, and the Romans had begun to regather their strength, they looked to re-assert their influence in the Balkans, and to curb the expansion of Philip. A pretext for war was provided by Philip's refusal to end his war with Attalid Pergamum, and Rhodes, both Roman allies. The Romans, also allied with the Aetolian League of Greek city-states (which resented Philip's power), thus declared war on Macedon in 200 BC, starting the Second Macedonian War. This ended with a decisive Roman victory at the Battle of Cynoscephalae (197 BC). Like most Roman peace treaties of the period, the resultant 'Peace of Flaminius' was designed utterly to crush the power of the defeated party; a massive indemnity was levied, Philip's fleet was surrendered to Rome, and Macedon was effectively returned to its ancient boundaries, losing influence over the city-states of southern Greece, and land in Thrace and Asia Minor. The result was the end of Macedon as a major power in the Mediterranean. [SEP] Knowledge 2: Classical music
It is in this time that the notation of music on a staff and other elements of musical notation began to take shape. This invention made possible the separation of the composition of a piece of music from its transmission; without written music, transmission was oral, and subject to change every time it was transmitted. With a musical score, a work of music could be performed without the composer's presence. The invention of the movable-type printing press in the 15th century had far-reaching consequences on the preservation and transmission of music.
Knowledge 1: Hellenistic period
Roman entanglement in the Balkans began when Illyrian piratical raids on Roman merchants led to invasions of Illyria (the First and, Second Illyrian Wars). Tension between Macedon and Rome increased when the young king of Macedon, Philip V harbored one of the chief pirates, Demetrius of Pharos (a former client of Rome). As a result, in an attempt to reduce Roman influence in the Balkans, Philip allied himself with Carthage after Hannibal had dealt the Romans a massive defeat at the Battle of Cannae (216 BC) during the Second Punic War. Forcing the Romans to fight on another front when they were at a nadir of manpower gained Philip the lasting enmity of the Romans; the only real result from the somewhat insubstantial First Macedonian War (215–202 BC). [SEP] Knowledge 2: Late Middle Ages
The main representatives of the new style, often referred to as ars nova as opposed to the ars antiqua, were the composers Philippe de Vitry and Guillaume de Machaut. In Italy, where the Provençal troubadours had also found refuge, the corresponding period goes under the name of trecento, and the leading composers were Giovanni da Cascia, Jacopo da Bologna and Francesco Landini. Prominent reformer of Orthodox Church music from the first half of 14th century was John Kukuzelis; he also introduced a system of notation widely used in the Balkans in the following centuries.

Answer: John Kukuzelis