Rubuta ci gaba don wannan sakin layi - Ptolemy IV shi ne ɗan na biyu kuma ɗan fari na Ptolemy III da matarsa Berenice II. An haife shi shekara biyu bayan mahaifinsa ya hau gadon sarautar Masar. Ptolemy IV yana da wata 'yar'uwa babba, Arsinoe III, da ƙananan' yan'uwa uku, Lysimachus (sunan da ba a sani ba), Alexander da Magas, duk an haife su a cikin 240s BC. Dukan dangin suna tunawa da rukuni na mutum-mutumi da aka kafa a Thermos da Delphi ta Aetolian League. A karkashin Ptolemy III, masarautar Ptolemaic ta kai ga mafi girma, ta ci nasara da masarautar Seleucid mai hamayya a Yaƙin Siriya na Uku (246<unk>241 BC), ta ba da kuɗin adawa da Girka ta Antigonid Macedonia, da kuma kula da kusan dukkanin gabashin tekun Bahar Rum. Duk da haka mulkin ya kuma kasance alama ce ta farko na 'yan asalin Masar da suka yi tawaye da mulkin Ptolemaic, a cikin 245 BC. A cikin shekaru na ƙarshe na mulkin Ptolemy III, Cleomenean War
(229 <unk> 222 BC) ya barke a Girka kuma, duk da karɓar babban tallafi na Ptolemaic, Cleomenes III na Sparta ya ci nasara gaba ɗaya ta hanyar haɗin gwiwar da Antigonid ya jagoranta kuma ya tilasta masa gudu zuwa Masar.