May 29, 1453 is known throughout the Greek world as a black anniversary — the day the Byzantine capital city of Constantinople fell to the invading Ottoman Turks.

A turning point in Western history, the fall of Constantinople was devastating to the Greek world and the beginning of centuries of occupation and enslavement.

Constantine XI, also known as Constantine Paleologos, led a valiant effort to defend the city until the final day of the siege when he was killed.

He could have walked away, unscathed, but chose to die fighting.

Before the beginning of the siege, Mehmed II, the leader of the Ottoman forces, made an offer to Constantine to surrender the city. Mehmed told him his life would be spared and he would be given the region of Mistras in the Peloponnesos to rule following his surrender of Constantinople.

Constantine’s famous “no” has gone down in history.

“To surrender the city to you is beyond my authority or anyone else’s who lives in it, for all of us, after taking the mutual decision, shall die out of free will without sparing our lives.”

Constantine’s death is the subject of conflicting stories. Some say he was beheaded and that his body was found and identified by his purple boots, while the Ottomans sent his head around Asia Minor as a display of Ottoman power. Most say he was never seen again, and was probably buried in a mass grave along with his soldiers.

Constantine’s last recorded words in battle were, “The city is fallen, but I am alive.”

An old Greek legend refers to Constantine XI as the “Marble King,” saying that when the Ottomans entered Constantinople, an angel rescued the emperor, turned him into marble and placed him in a cave under the earth near the Golden Gate in Istanbul, where he waits to be brought to life again and reestablish Christian Constantinople.

Centuries later and looking back at one of history’s most decisive battles, the fall of Constantinople changed Europe — and the world — forever.

The city’s collapse marked the end of Byzantium, which led to the end of the Middle Ages and the beginning of the Renaissance in Europe.

The loss of Constantinople also severed European trade links with Asia, leading many to begin seeking routes east by sea and leading to the age of exploration.

Many of the city’s leading Greek scholars fled west to the Italian city-states, bringing with them priceless knowledge and rare manuscripts such as Greco-Roman literary classics.

The scholars were welcomed not only in Italy but throughout European capital cities. They also possessed a knowledge of Greek, which enabled their students to read the works of ancient Greek authors such as Homer for the first time.

In Italy the works were translated into Latin, and the information that they contained, much of which was from classical Greece nearly 1,000 years before, played an influential role in the intellectual Renaissance life and further development of Europe.