Final answer:
The main idea is that after Alexander's death, Ptolemy took control of Egypt, founded a dynasty, and cultivated a Greco-Egyptian culture.
Step-by-step explanation:
The main idea of the section "Alexander Died Before Seeing His City Come to Life" appears to revolve around the aftermath of Alexander the Great's death and the legacy it left behind, especially in relation to the city of Alexandria. After Alexander died in 323 BC, his general Ptolemy seized control of his body and Egypt. Ptolemy then proclaimed himself king and became the ruler of Alexandria, where he established a dynasty that would last nearly three centuries. This action set the stage for a new era in Egypt that combined Greek and Egyptian cultures, majorly influencing the governance and religion of the region as the Ptolemies adapted to their new role as pharaohs.