A popular motif in medieval literature and ancient philosophy referring to the uncertainty of Fate. The Wheel of Fortune is a symbol of the goddess Fortuna, famous for her caprice. She may be depicted as “larger than life”, blindfolded as being “blind to justice”, spinning the wheel at random, or standing/flying on the rolling ball. “The Prince” Machiavelli states that Fortune only rules one half of men's fate, the other half being of their own will.
enlarge image Rota Fortunae, Carmina Burana illumination, 1230, Bavarian State Library
Image in the public domain source
Carmina Burana is one of the most important medieval collection of Goliard love and vagabond songs. The illumination shows the wheel of fortune with four human figures, that stands for four stages of life, labelled as regnabo (I shall reign), regno (I reign), regnavi (I have reigned) and sum sine regno (I have no kingdom).
An example in the ARTS -> Carmina Burana
O Fortune, like the moon of ever changing state, you are always waxing or waning; hateful life now is brutal, now pampers our feelings with its game; poverty, power, it melts them like ice.
Fate, savage and empty, you are a turning wheel, your position is uncertain, your favour is idle and always likely to disappear; covered in shadows and veiled you bear upon me too; now my back is naked through the sport of your wickedness.
The chance of prosperity and of virtue is not now mine; whether willing or not, a man is always liable for Fortune's service. At this hour without delay touch the strings! Because through luck she lays low the brave, all join with me in lamentation!
FORTUNAE PLANGO VULNERA
I mourn the blows of Fortune with flowing eyes, because her gifts she has treacherously taken back from me. Opportunity is rightly described as having hair on her forehead, but there usually follows the bald patch at the back.
On the throne of Fortune I had sat elated, crowned with the gay flower of prosperity; however much I flourished, happy and blessed, now I have fallen from the pinnacle, deprived of my glory.
The wheel of Fortune turns; I sink, debased; another is raised up; lifted too high, a king sits on the summit him beware of ruin! Under the axle we read, Queen Hecuba.
REF -> a poems on the subject of Fortune in the medieval manuscript Carmina Burana.
Poems: O Fortuna at http://www.tylatin.org/extras/cb1.html and
Fortunae Plango Vulnera at http://www.tylatin.org/extras/cb2.html