Answer
Nestorius, the Patriarch of Constantinople, was famously embroiled in a dispute with Cyril of Alexandria, another prominent church leader. The disagreement centered around Nestorius' theological views, particularly his emphasis on the distinction between the divine and human natures of Christ. Cyril, on the other hand, championed the idea of the hypostatic union, asserting that Christ's divine and human natures were inseparably united in a single person.