Debauched son of Ptolemy III during whose inattentive reign Egypt lost most of the stability & influence it had achieved under the first three Macedonian pharaohs. He began his reign (221 BCE) by ordering the murder of his mother [Berenice II], uncle [Lysimachus] & younger brother [Magas]. A drunken reveler, Ptolemy regularly depended on advice from incompetent court favorites. His most able general defected to the Syrian ruler Antiochus III. Faced with a string of military defeats Ptolemy ceded most of the territory Egypt had occupied in Asia Minor, Syria & Palestine to his energetic Seleucid rival. Even his plan to train native Egyptians to strengthen his army backfired, when Egyptians launched the first major revolt against Macedonian rule in more than a century (210 BCE). Ptolemy died soon after he lost upper Egypt to insurgents, but his death was kept a secret for more than a year while his henchmen eliminated potential rivals.

References: Josephus, Antiquities 12.130-131.
                  Polybius, Histories 2.51; 15.25-34.
                   Justin, Epitome 30.1-2.

Other resources on line:

• Ptolemy IV Philopator I  - chapter 3 of E. R. Bevan's 1927 classic The House of Ptolemy [on Bill Thayer's Lacus Curtius].

• Ptolemy IV - Christopher Bennett's annotated Egyptian Royal Genealogy provides detailed references to sources.

• Great Revolt of the Egyptians (205-186 BCE) -  illustrated translation & explication of Greek & Egyptian sources describing the 20 year native uprising in upper Egypt that Ptolemy IV left for his heir [UCal at Berkeley].

• Ptolemy IV Philopator - Jona Lendering lists biographical data & key dates [Livius: Articles in Ancient History].

• Ptolemy IV Philopator - entry in Wikipedia's web.

Like his father, Ptolemy IV did not issue coins bearing his own image.  This silver tetradrachma from the Egyptian military mint in Phoenicia was issued in 202 BCE, three years after his death, by Ptolemy V to commemorate his deified father. The face depicts Ptolemy IV with diadem. The reverse bears the traditional Ptolemaic design: an eagle surrounded by the inscription: Ptolemaiou Basileos ["of King Ptolemy"]. The fine quality of the design & stamping, as well as the minimal wear, shows that this coin did not circulate widely in the marketplace.