Sophia Fominichna Palaiologina or Paleologue (Russian: София Фоминична Палеолог, romanized: Sofiya Fominichna Paleolog; born Zoe Palaiologina; Medieval Greek: Ζωή Παλαιολογίνα; c. 1449 – 7 April 1503) was a Byzantine princess from the Palaiologos imperial dynasty and the grand princess of Moscow as the second wife of Ivan III of Russia.

[3] Her mother was Catherine, daughter and heiress of Centurione II Zaccaria, the last independent Prince of Achaea and Baron of Arcadia.

The marriage between Thomas Palaiologos and Catherine Zaccaria produced four children: Helena (later wife of Lazar Branković, Despot of Serbia), Zoe, Andreas, and Manuel.

Seven years later, in 1460, the Ottoman army attacked Morea and quickly breached the Hexamilion wall across the Isthmus of Corinth, which was too long to be effectively manned and defended by Thomas' forces.

Zoe and her brothers remained in Petriti, a fishing port on the southeast coast of Corfu, until 1465, when their dying father recalled them to Rome.

After the death of Thomas Palaeologus, his eldest son, Andreas, claimed the Imperial title, but he sold his rights to several European monarchs and ultimately died in poverty.

Sophia was apparently not obliged to follow the custom of isolation[10] that was practiced by elite Russian women among the wealthy boyars and the royal family.

[5] The Venetian ambassador, Ambrogio Contarini, wrote that in 1476 he had an audience with the Grand Duchess, who received him politely and kindly, and respectfully asked about the Doge.

These precautions led Vissarion, Bishop of Rostov, to warn the Grand Duke that his excessive attachment to his wife and children would be his destruction.

[5] It is believed that Sophia introduced grand Byzantine ceremonies and meticulous court etiquette into the Kremlin, pleased with the idea of Moscow as a Third Rome.

The princely family increased significantly: between 1474 and 1490, as the Grand Princess gave birth to eleven children, five sons and six daughters.

Another source of tension appeared in the Russian court in January 1483, when Ivan the Young married Elena, daughter of Stephen III the Great, Prince of Moldavia.

In particular, the Grand Princess was unable to obtain government posts for her relatives: Her brother, Andreas, departed from Moscow with nothing, and her niece, Maria (wife of Vasily Mikhailovich, Hereditary Prince of Verey-Belozersky), was forced to flee to Lithuania with her husband, an event that further undermined Sophia's position at court.

According to sources, Sophia had arranged her niece's marriage to Prince Vasily in 1480, and in 1483 she gave Maria some jewelry that belonged to Ivan III's first wife.

Sophia wrote to a Venetian doctor named Leon, who imprudently promised Ivan III that he could cure the heir to the throne.

According to chronicles, Ivan III suddenly changed his mind and imprisoned both Grand Prince Dmitry and his mother, Elena, placing them under house arrest, surrounded by guards.

She was buried in a massive white stone sarcophagus in the crypt of the Ascension Convent in the Kremlin, next to the grave of Maria of Tver, the first wife of Ivan III.

The Ascension Convent was demolished in 1929 as ordered by the Soviet government, and the remains of Sophia and of other royal women were transferred to an underground chamber in the southern extension of the Cathedral of the Archangel.

[21] She is a minor character in Dorothy Dunnett's acclaimed series of historical novels, known as The House of Niccolò, which is set in the late 15th century.