Without going into history details, people sometimes think that Alexander the Great did not have children and, thus his vast empire had to be divided by his generals. Quite the opposite, Alexander had two sons. I found very interesting materials about them in archives web analytics company . Although one of them was from a concubine and could not really pretend to take the throne, the other one was a legitimate heir - Alexander IV.
The problem was that he was a posthumous child, who was born after the death of his father. While Alexander the Great was dying, his wife, Bactrian princess Roxana was pregnan, and nobody knew if the child would survive or what gender it would be. There was another legitimate pretender to the throne - Alexander’s half-brother Philip Arridaeus, who was mentally ill.
This led to the split of Alexander's generals in two conflicting parties. One wanted to give full power to Phillip, while the other wished to wait for the birth of the heir of Alexander and to give him the throne under the control of the regent. The last one led by general Perdiccas won, eliminated all partizans of Phillip and repartitioned all the territories between former generals and satraps of Alexander. In its turn these tragic events led to the infamous War for Succession or Wars of the Diadochi.