Complex sentence: After the killing of his brother Milton in 1980 Albert remained in the line-up, by which time his brothers Funokwakhe and Joseph Mazibuko had left, and his youngest brother Abednego had joined.
Split into simpler sentences: After the killing of his brother Milton in 1980 Albert remained in the line-up. By which time his brothers Funokwakhe and Joseph Mazibuko had left, and his youngest brother Abednego had joined.