The Araluen–Gallican War, lasting from 656 until 658 CE, was a naval war between the rival Kingdom of Araluen and the Kingdom of Gallica, along with the latter's allies, Iberion and Toscano. It was mostly a naval war and was the cause of a naval arms race between mutliple powers. The battle saw the Royal Navy of Araluen gain supremacy in the seas over its powerful rivals, the Gallican Royal Navy and Iberian Armada. It also began a wave of colonization over the Far East, allowing Araluen to seize control of some of the region's best ports before Gallica and Iberion.
With the conclusion of Horace's successful military mission to Nihon-Ja, it led to greater cooperation and contact between Araluen, the other western states, and those of the Far East. The Araluens had the advantage but still vied for influence and trade rights with the lords of Gallica and the merchants from Iberion. Soon they began to establish their own spheres of influence and acquiring colonial ports, which served as centers of supply on the trade routes through the Eastern Ocean and Sea of Blood. King Duncan of the Araluen sought to position his island kingdom as the dominant western power in eastern trade.
However, King Henri of Gallica also saw the opportunity to strengthen his own position with newfound wealth that could be gained from trade in the east, while the individual Gallican feudal lords also coveted the potential earnings. Thus in a rare instance of cooperation, the court of the Gallican king and several of the most powerful lords decided to work together to spread Gallican influence in the east. Meanwhile, King Pedro of Iberion also saw the opportunity in extended trade to lift his kingdom out of poverty. Other western countries, such as Toscano and Arrida, also had their own interests in gaining control over eastern trade and resources.
It was during this time that maritime technology was becoming rapidly developed to protect and increase trade between the east and west. The Royal Navy of Araluen quickly became the dominant force, as the country's wealth and earliest ties to the region allowed it to construct and develop an effective naval fleet and system of safe ports. King Duncan saw this as necessary and became the Royal Navy's main sponsor. By 650, the Gallican lords, with support of the king, also began building a Gallican Royal Navy, while the king of Iberion oversaw the buildup of the Iberian Armada. This alarmed King Duncan and the Araluen admiralty, which saw this as a direct challenge to their supremacy in the area.
By 652, Iberian and Gallican ships began to arrive and establish ports in eastern lands as well, increasing their own trade with them.