In his Life of Pyrrhus, Plutarch records that Hannibal ranked him as the greatest commander the world had ever seen, though in the Life of Titus Quinctius Flamininus, Plutarch writes that Hannibal placed him second after Alexander the Great.
This latter account is also given by Appian.
While he was a mercurial and often restless leader, and not always a wise king, he was considered one of the greatest military commanders of his time.

Pyrrhus was known for his benevolence.
As a general, Pyrrhus's greatest political weaknesses were his failures to maintain focus and to maintain a strong treasury at home (many of his soldiers were costly mercenaries).

His name is famous for the term "Pyrrhic victory" which refers to an exchange at the Battle of Asculum.
In response to congratulations for winning a costly victory over the Romans, he is reported to have said: "If we are victorious in one more battle with the Romans, we shall be utterly ruined".

Pyrrhus and his campaign in Italy was effectively the only chance for Greece to check the advance of Rome towards domination of the Mediterranean world.
Rather than banding together, the various Hellenistic powers continued to quarrel among themselves, sapping the financial and military strength of Greece and to a lesser extent, Macedon and the greater Hellenistic world.
By 197 BC, Macedonia and many southern Greek city-states became Roman client states; in 188 BC, the Seleucid Empire was forced to cede most of Asia Minor to Rome's ally Pergamon (Pergamum).
Rome inherited that state, and most of Asia Minor in 133 BC.
Total Roman domination over Greece proper was marked by the destruction of Corinth in 146 BC; Greece then formed an integral part of the Roman world leading into the Byzantine period.

Pyrrhus wrote memoirs and several books on the art of war.
These have since been lost, although, according to Plutarch, Hannibal was influenced by them, and they received praise from Cicero.

Pyrrhus was married five times: his first wife Antigone bore him a daughter called Olympias and a son named Ptolemy in honour of her stepfather.
She died in 295 BC, possibly in childbirth, since that was the same year her son was born.
His second wife was Lanassa, daughter of King Agathocles of Syracuse (r. 317–289 BC), whom he married in about 295 BC; the couple had two sons, Alexander and Helenus; Lanassa left Pyrrhus.
His third wife was the daughter of Audoleon, King of Paeonia; his fourth wife was the Illyrian princess Bircenna, who was the daughter of King Bardylis II (r. c. 295–290 BC); and his fifth wife was the daughter of Ptolemy Keraunos, whom he married in 281/280 BC.
Portraits of Pyrrhus as have come down to us do not necessarily reflect his likeness.
In his Life of Pyrrhus, Plutarch records that Hannibal ranked him as the greatest commander the world had ever seen, though in the Life of Titus Quinctius Flamininus, Plutarch writes that Hannibal placed him second after Alexander the Great. This latter account is also given by Appian. While he was a mercurial and often restless leader, and not always a wise king, he was considered one of the greatest military commanders of his time. 
Pyrrhus was known for his benevolence. As a general, Pyrrhus's greatest political weaknesses were his failures to maintain focus and to maintain a strong treasury at home (many of his soldiers were costly mercenaries). 
His name is famous for the term "Pyrrhic victory" which refers to an exchange at the Battle of Asculum. In response to congratulations for winning a costly victory over the Romans, he is reported to have said: "If we are victorious in one more battle with the Romans, we shall be utterly ruined".
Pyrrhus and his campaign in Italy was effectively the only chance for Greece to check the advance of Rome towards domination of the Mediterranean world. Rather than banding together, the various Hellenistic powers continued to quarrel among themselves, sapping the financial and military strength of Greece and to a lesser extent, Macedon and the greater Hellenistic world. By 197 BC, Macedonia and many southern Greek city-states became Roman client states; in 188 BC, the Seleucid Empire was forced to cede most of Asia Minor to Rome's ally Pergamon (Pergamum). Rome inherited that state, and most of Asia Minor in 133 BC. Total Roman domination over Greece proper was marked by the destruction of Corinth in 146 BC; Greece then formed an integral part of the Roman world leading into the Byzantine period.
Pyrrhus wrote memoirs and several books on the art of war. These have since been lost, although, according to Plutarch, Hannibal was influenced by them, and they received praise from Cicero.
Pyrrhus was married five times: his first wife Antigone bore him a daughter called Olympias and a son named Ptolemy in honour of her stepfather. She died in 295 BC, possibly in childbirth, since that was the same year her son was born. His second wife was Lanassa, daughter of King Agathocles of Syracuse (r. 317–289 BC), whom he married in about 295 BC; the couple had two sons, Alexander and Helenus; Lanassa left Pyrrhus. His third wife was the daughter of Audoleon, King of Paeonia; his fourth wife was the Illyrian princess Bircenna, who was the daughter of King Bardylis II (r. c. 295–290 BC); and his fifth wife was the daughter of Ptolemy Keraunos, whom he married in 281/280 BC. Portraits of Pyrrhus as have come down to us do not necessarily reflect his likeness.
Pyrrhus of Epirus