Below are given some sentences out of which the sentence numbered 4 has been correctly placed. The rest of the sentences A,B,C,D,E,F need to be arranged correctly in order to form a logical order.

A.      He was born in Pella in 356 BC and succeeded his father Philip II to the throne at the age of 20.

B.      He was undefeated in battle and is widely considered one of history's most successful military commanders.

C.      He spent most of his ruling years on an unprecedented military campaign through Asia and northeast Africa, and by the age of thirty he had created one of the largest empires of the ancient world, stretching from Greece to northwestern India. 

4.       In 334 BC, he invaded the Achaemenid Empire (Persian Empire) and began a series of campaigns that lasted 10 years.

D.      Following the conquest of Anatolia, Alexander broke the power of Persia in a series of decisive battles, most notably the battles of Issus and Gaugamela.

E.       He subsequently overthrew Persian King Darius III and conquered the Achaemenid Empire in its entirety.

F.       Alexander the Great was a king of the ancient Greek kingdom of Macedon and a member of the Argead dynasty.