In a political context, the phrase means to generate public approval, not by excellence in public service or public policy, but by diversion, distraction or by satisfying the most immediate or base requirements of a populace, by offering a palliative: for example food (bread) or entertainment (circuses).
Juvenal, who coined the phrase, used it to decry the "selfishness" of common people and their neglect of wider concerns. The phrase implies a population's erosion or ignorance of civic duty as a priority.
This phrase originates from Rome in Satire X of the Roman satirical poet Juvenal (c. 100 CE). In context, the Latin panem et circenses (bread and circuses)
identifies the only remaining interest of a Roman populace which no
longer cares for its historical birthright of political involvement.
Here Juvenal displays his contempt for the declining heroism
of contemporary Romans, using a range of different themes including
lust for power and desire for old age to illustrate his argument.[6] Roman politicians passed laws in 140 CE to keep the votes of poorer citizens, by introducing a grain dole: giving out cheap food and entertainment, "bread and circuses", became the most effective way to rise to power:
"... Already long ago, from when we sold our vote to no man, the People
have abdicated our duties; for the People who once upon a time handed
out military command, high civil office, legions — everything, now
restrains itself and anxiously hopes for just two things: bread and
circuses."
Juvenal here makes reference to the Roman practice of providing free wheat to Roman citizens as well as costly circus games and other forms of entertainment as a means of gaining political power. The Annona (grain dole) was begun under the instigation of the popularis politician Gaius Sempronius Gracchus in 123 BCE; it remained an object of political contention until it was taken under the control of the autocratic Roman emperors.
Charot
