The Malagrotta Affair was one of the major events that lead up to the Reunification War. The incident occurred in February of 2573 and was a 'misunderstanding' on all sides during an increasingly volatile time. Both the Star League and Federated Suns had become angry over the continued indifference of the Taurian Concordat; the Periphery nation would not bow or acknowledge the Inner Sphere's authority. But the Concordat was not entirely clean in this debacle, as long-buried records imply that the 'error' in navigation was less accident and more intent to gauge House Davion's resolve. 
In 2499 the Taurian Concordat explored the Malagrotta star system and discovered on one of the moons orbiting the gas giant DeeCee was tremendously rich in titanium. But right on their heels came a Davion exploratory mission in the same system. Though colonized first by the Taurians, mining rights to the moon of Fontana were granted to both Taurian and Davion mining concerns following the Omsol Accord in 2511. This treaty was one of the very few times a resolution was made without military force, a great rarity of the era. The treaty also stipulated that neither the Concordat nor the Federated Suns could establish a military presence in the system. For over 60 years separate mining operations were successful for both nations when, during the escalating hostilities leading to the Reunification War, a small Taurian WarShip flotilla entered the system accidentally. The frightened Davion mining crews immediately notified a Davion fleet that happened to be waiting in a nearby system. The larger Davion fleet jumped into the system and found the five Taurian vessels orbiting the moon. Unable to communicate with the 'invading' Warships, the Davion officers ordered an attack, destroying two Wagon Wheel-class Warships and capturing a third vessel.  
Though the Taurians were technically in the wrong, the Davion response went far overboard. First Lord Ian Cameron ordered both parties to come to him and let him mediate. However, Alexander Davion attempted to cover up the errors of his officers, and Protector Caterina Calderon was not kind in her assertion that the matter was solely between the Federated Suns and the Taurian Concordat; the First Lord and his Star League had no right to control mediation. Thus, an irate First Lord declared the Taurians in the wrong and even commented "We have been compassionate long enough. I'll be damned if I am going to pull anymore punches."  Several months later, Protector Caterina Calderon offered an apology and restitution. However, the apology was too little and too late to prevent the oncoming cataclysm. Nineteen months after the Affair, Ian Cameron delivered the Pollux Proclamation and set what would become the Reunification War into motion.
- Field Manual: Periphery, p. 47
- The Periphery, p. 20
- The Star League, p. 44