Ptolemy Philadelphus (The Book of Shadows)

Ptolemy Philadelphus was the son of Ptolemy Lagus and Barbara Wright in an alternate timeline. He shared a name with Ptolemy's son in the original timeline and was born not long after Barbara and Ptolemy met in 322 BC.

When he was eight years old, Egypt was caught in a power struggle between Ptolemy Lagus and Perdiccas. During the chaos, Barbara left Philadelphus behind while she searched for the First Doctor.

The timeline was averted when Barbara read from The Worshipful and Ancient Law of Gallifrey, rewriting time such that she had never arrived in Egypt during that time. (PROSE: The Book of Shadows)