Complex sentence: The family lived in Allston, Massachusetts, until Bloomberg was two years old, when they moved to Brookline for the next two years, finally settling in Medford, a Boston suburb, where he lived until after he graduated from college.
Split into simpler sentences: The family lived in Allston, Massachusetts, until Bloomberg was two years old. They moved to Brookline, Massachusetts, for the next two years, finally settling in Medford, a Boston suburb, where he lived until after he graduated from college.