The Ottoman empire, among the greatest the world has seen, was founded by the eponymous Osman, a minor Turkish chieftain from northwestern Anatolia. His main rival was the declining and enfeebled Byzantine empire, which had once controlled all of Anatolia, though by the late 13th century encroaching Turks had driven it to the westward edges of the peninsula.

Still, at the turn of the 14th century, the Ottomans themselves remained a minor power, one of a number of Turkish petty states in western Asia Minor. Osman enters recorded history—recorded, that is, by contemporary Byzantine historian George Pachymeres—around 1301 when he led a party of 100 nomads on a night raid against a Byzantine force north of the city of Nicaea, which he had been harassing.

At a place called Telemaia, Osman and his band literally caught the enemy sleeping, riding in among them and spearing them as they lay on the ground. Thus rudely awakened, the Byzantines rallied and pursued their attackers, who fell back on nearby hills. There, the Turkish horsemen halted and drove back their pursuers with volleys of arrows. In the resulting melee, the Byzantine commander Mouzalon would have been captured were it not for a daring rescue by one of his bravest men.

The back story of the Ottoman empire began in 1204, nearly a century before Osman’s fight at Telemaia, when Latin Christian (Catholic) soldiers of the misbegotten Fourth Crusade sacked Constantinople, terrorizing its Orthodox Christian populace and driving the Byzantine government from its capital. For the next half century, the principal Byzantine state in exile was the empire of Nicaea, in western Anatolia. Guarding its eastern frontier was, in the words of one historian, a “localized militia” of sorts, whose members were granted tax exemptions as thanks for defending their lands from the Turks.

Founded and ably led by the House of Laskaris, the Nicaean state experienced several decades of relative peace and prosperity, winning the dynasty the support of the populace. Things fell apart, however, after third emperor Theodore II Laskaris died in 1258, leaving his 7-year-old son, John IV Laskaris, as ostensible heir to the throne. Scarcely four months later Michael Palaiologos, an ambitious statesman-general who had forcibly claimed the position of regent to John IV, proclaimed himself co-emperor, as Michael VIII.

Ruling as de facto emperor, Michael commanded the imperial forces and in 1261 managed to wrest back Constantinople, restoring the Byzantine empire and cementing his legitimacy. No longer willing to share the throne, he ordered the blinding of John that year—reportedly on his 11th birthday—rendering the boy ineligible to reign. (John spent the remainder of his life as a monk.) In response to Michael’s cruelty, Patriarch Arsenios Autoreianos, the leading cleric of the Orthodox Church, excommunicated the emperor. Arsenios’ action was intolerable to Michael, as to effectively rule, any Byzantine emperor had to have the support of the church hierarchy. It took some doing, but in 1265 the scheming emperor managed to depose Arsenios and send him into exile.

That didn’t end the controversy, as a number of clergymen in Asia Minor sided with Arsenios in denunciation of Michael. They ultimately formed an opposition party within the church dubbed the Arsenites. Regarding the emperor with general hostility, its members refused to accept the legitimacy of patriarchs appointed by Michael. But the Arsenite schism only spelled the beginning of the emperor’s problems. Through his own misguided policies he managed to further alienate his Anatolian subjects.

Once he had retaken Constantinople, Michael had to be continually on guard against renewed crusades from papal armies. To defend the western approaches of the empire, he needed more men, for which he looked to the eastern frontier. In a brilliant if devious move, he revoked the eastern militia’s tax-exempt status, instead paying its members salaries for their continued military service. Left financially dependent on the state, the guardians accepted transfer to the west with little complaint. Those transfers in turn severely weakened the eastern defenses, crushing morale among the remaining guardians. Some went so far as to defect to the ascendant Turks. According to Pachymeres, the emperor “spent all his energies on the west,” disregarding the very real danger massing along the eastern frontier.

Michael VIII had weakened his eastern defenses at exactly the wrong time, as by the late 13th century the Turks were on the move. In 1242, the Mongols had invaded Asia Minor and defeated the Seljuk sultanate, the Turkish state to the east of the old Nicaean state. The westward-riding Golden Horde drove before them a wave of Turkish nomads, bound straight for the Byzantine frontier. Antithetical to the empire’s Christian roots, the new arrivals were Muslim (although not always theologically orthodox) whose religious fervor was sustained by clerics in their ranks. Fighting in bands of mounted archers, the hard-pressed Turks tested Byzantine defenses, launching raids, in the words of historian Donald M. Nicol, “with the zeal of religious fanatics and with the desperation of men for whom there was no chance of retreat.”

To ameliorate ongoing threats from the west, Michael VIII brokered a deal with the papacy in 1274, agreeing to a union of the Catholic and Orthodox churches—meaning, of course, the latter would be subject to the former. In exchange the papacy would forbid western rulers from launching attacks on Constantinople. When the majority Orthodox Christians in Byzantium refused to go along with such a scheme, Michael responded with a heavy hand, meting out blindings, mutilations, imprisonment and/or exile to anyone in opposition. He wound up tearing apart Byzantine society and, according to Nicol, “undermined the general will of the people to cooperate with their government for a true restoration of the empire.”

Michael VIII died in 1282 and was succeeded by his son, Andronikos II, a wholly different sort of man than his father. Whereas Michael was ruthless and decisive, Andronikos was mild-mannered and genuinely pious, immediately canceling his father’s deal with the papacy and doing his best to appease disaffected Arsenites in the Orthodox Church.

Unfortunately, Andronikos’ milder nature was borne out during his reign by his mild approach to policymaking. This was partly due to scarcity—his father’s heavy spending had depleted the treasury. That want especially hampered Andronikos’ efforts in Anatolia, where the empire’s fortunes continued to decline. In the face of increasing Turkish attacks, much of the Byzantine population abandoned the countryside and fled to Constantinople, other fortified cities or the Aegean islands. They had good reason, as any Christian taken alive by the Turks was liable to find himself sold into slavery. In an effort to stem the exodus, Andronikos spent a few years rebuilding fortifications in Asia Minor. But the writing was on the wall.

The institutions he had inherited from his father were breaking down. Previous emperors, including Michael, had supported Byzantine regular soldiers via the institution of pronoia—an imperial grant, not of land, but of revenues. For example, in reward for his service, a soldier might be granted the taxes paid by peasants working a particular plot of land (although the distinction between land and revenue broke down over time). Originally, the pronoia were nontransferable and would revert to the crown on the beneficiary’s death. But by Andronikos’ reign, families increasingly regarded the grants as hereditary, thus depriving the government of a significant source of revenue. The shift also saw large landowners accumulating pronoia rights over more and more property. Worst of all, the link between pronoia and military service was rapidly dissolving. It was imperative Andronikos fix the broken system.

Accordingly, in 1298, the emperor sent statesman-general John Tarchaneiotes to Anatolia to institute a set of reforms. But Michael VIII’s legacy continued to haunt Andronikos, for Tarchaneiotes was an Arsenite—a supporter of the patriarch who had excommunicated Michael for having blinded young John IV—while the patriarch at the time was an anti-Arsenite opposed to Tarchaneiotes’ appointment. To placate the patriarch, Andronikos required Tarchaneiotes to swear an oath of allegiance to the emperor before setting out.

Though Tarchaneiotes had some initial successes in Anatolia, political controversies ultimately derailed his mission. Soldiers who had lost pronoia income as a result of his reforms brought charges of treason against him before the local bishop, an anti-Arsenite. The unpopular Tarchaneiotes was forced to flee Anatolia, around mid-1300, and his reforms were abandoned.

A year later, Osman defeated Mouzalon at Telemaia. The situation in Anatolia looked bleak. Then something happened that must have brought a ray of hope to Andronikos.

Late in 1301 upward of 10,000 warriors, accompanied by their families, appeared on Byzantium’s northern frontier requesting admittance. They were Alans, an Iranian people of the north Caucasus, many of whose warriors had served in the Mongol armies of the Golden Horde. The Alans were also Orthodox Christians whose ancestors had been converted by Byzantine missionaries. (Their present-day descendants are the Ossetians, a people recently caught up in a dispute between Russia and Georgia.)

The arrival of the Alans meant Andronikos would have the manpower for campaigns he had planned in Asia Minor. However, the empire would first need to equip the warriors and provide them with horses—an expensive proposition. Thus Andronikos levied additional taxes on the population. According to the 14th-century Byzantine historian Nicephorus Gregoras, tax collectors seized both money and mounts from the people, leaving many destitute and resentful.

Then the Alans themselves became problematic, demanding to fight as a unit. Andronikos and his generals denied the request. Some historians claim that decision only hampered the Alans’ combat effectiveness. But while splitting up the Alans may have sapped their morale—many deserted and returned to their families, since resettled in Thrace—the Byzantines had no choice, as between 1299 and 1301, the Turks had advanced along the western Anatolian frontier.

Andronikos sent the Alan reinforcements where and when needed. In the spring of 1302 ,one group of Alans, under the emperor’s son and coruler Michael IX, headed south to confront Turks in the onetime Nicene stronghold of Magnesia, but within months that force dissolved in mass desertions. Meanwhile, another group of Alans headed east across the Bosporus to confront Osman, then on the move. The latter’s victory at Telemaia, while small-scale, had brought him prestige and convinced other Turks to join him. His ranks thus swelled, Osman moved north against the walled city of Nicomedia, at the base of the small peninsula pointing dagger-like toward Constantinople.

The Alans were to reinforce the Byzantine troops guarding Nicomedia, which remained under Mouzalon’s command despite his recent defeat at Telemaia. Mouzalon’s combined Byzantine-Alan force comprised some 2,000 men. Advancing to meet them in late July 1302 was a Turkish force of some 5,000 mounted warriors under Osman. The opposing armies met in battle at Bapheus, a location lost to history, though known to have been within running distance of Nicomedia.

According to historian Pachymeres, the Byzantine troops at Bapheus were initially eager to defend their native soil. That is, until Mouzalon, showing no greater military acumen than when caught napping at Telemaia, decided to confiscate horses and equipment from his Byzantines and redistribute them to the Alans. Predictably, Byzantine morale collapsed, and their attacks against the Turks lacked conviction.

The Turks sensed that lack of resolve, and when they launched their own attack, they quickly gained the upper hand. Pachymeres described the match as unequal both “in number and in will.” Those Byzantines not killed took to their heels in flight toward Nicomedia.

Then the Alans went into action, proving their worth. Using tactics they had learned from the Mongols, they rode around the Turkish flank firing slantwise volleys of arrows. But while their needling assault bought time for the Byzantines to flee, the Alans sustained such heavy casualties that the Turks managed to hold the field and claim victory. Osman’s men followed up by plundering nearby districts, while the surviving Byzantines remained holed up in Nicomedia.

From then on the nascent Ottomans held the momentum. They initially focused on taking the fortified cities of Anatolia in turn. Their efforts came to fruition during the reign of Osman’s son Orhan (1323–62), who defeated a Byzantine advance into northwestern Anatolia at the Battle of Pelekanon in 1329, took Nicaea in 1331 and captured Nicomedia in 1337. In the 1350s the Ottomans began their conquest of the Balkans. Finally, in 1453, under Mehmed II, they took Constantinople itself, bringing the Byzantine empire to an end. Thus firmly established, the Ottoman empire would survive until World War I, when like the patchwork of previous human dynasties, it too fell mortally wounded.

Richard Tada has a doctorate in history from the University of Washington and is a frequent contributor to Military History and Military History Quarterly. For further reading he recommends The Late Byzantine Army: Arms and Society, 1204–1453, by Mark C. Bartusis, and The Last Century of Byzantium, 1261–1453, by Donald M. Nicol.

This story was published in the November 2019 issue of Military History Magazine. Subscribe here.