Osman I, the founder of the Ottoman Empire, embarked on a campaign that would set the stage for an expansive and influential state. Invading the territory of Nicomedia, located in present-day Turkey, his military action was not merely a quest for land but also a broader strategy to consolidate power and establish dominance against the declining Byzantine Empire. The significance of this invasion lies in its role as a catalyst for the Sunni Muslim response to the weakening of Christian Byzantine authority in Anatolia. By leading troops into these regions, Osman sought not only to grab territory but also to inspire loyalty among the Turkic peoples and create an administrative framework for what would evolve into one of history's most formidable empires.

The initial incursion into Nicomedia showcased Osman's military prowess and strategic foresight, as he capitalized on the political chaos and fragmentation in the Byzantine territories. The newly emerging Ottoman state would build upon this base, expanding inward and eventually reaching across Southeastern Europe, Western Asia, and North Africa. One remarkable aspect of Osman's approach was the incorporation of different cultural elements from the diverse regions he conquered, leading to a cosmopolitan character within the Ottoman Empire. This diversity would later influence administrative policies, military expansions, and trade networks, reinforcing the foundation laid during this early phase.

In addition to territorial gains, Osman I's actions were recognized as instrumental in rallying local tribes and forming alliances that were critical to the strength of his regime. The invasion of Nicomedia can thus be seen as an essential starting point for the Ottoman state, an event that would resonate through centuries of history, as it marked the inception of a dynasty that governed for over six centuries.