1378 is encountered both as a natural number and as a calendar year in the late Middle Ages. As a number it follows 1,377 and precedes 1,379; as a year it falls in the 14th century, a period of political realignment, social unrest and cultural change across Europe.
Mathematical properties
As an integer, 1378 is even and composite. Its prime factorization is 2 × 13 × 53, so it has a set of positive divisors given by combinations of those primes. In Roman numerals it is written MCCCLXXVIII. In common positional bases it appears as 10101100010 in binary, 0x562 in hexadecimal and 2542 in octal. The sum of its proper divisors is smaller than the number itself, which classifies 1378 as a deficient number.
Notable events of the year 1378
The year 1378 is most often remembered for ruptures in religious and civic order that had long-term consequences. Two events stand out:
- The papal crisis: Following the death of Pope Gregory XI in early 1378, the election of an Italian pope, Urban VI, produced deep divisions among the cardinals. Discontented cardinals later elected a rival pope based in Avignon, opening the period known as the Western Schism (a split in allegiance among European states and Christian communities that endured for decades).
- The Ciompi Revolt in Florence: In July 1378, wool workers and other lower-class laborers in Florence rose up against guild-dominated civic structures. The Ciompi briefly seized power, forcing concessions and exposing tensions between organized guilds, merchant elites and urban labor.
These disturbances coincided with broader conflicts such as the continuing Hundred Years' War and localized struggles for authority across the Holy Roman Empire and Iberia.
Political succession and wider significance
In Central Europe, the death of Holy Roman Emperor Charles IV late in 1378 brought dynastic change: his son, Wenceslaus, succeeded to his hereditary lands and titles. The transitions of leadership and the church's division weakened customary channels of legitimacy and contributed to instability in politics and diplomacy. The schism in particular eroded papal prestige and forced secular rulers to choose allegiances, shaping late-medieval European alliances.
Legacy and context
Although 1378 itself is a single year, its events illustrate larger currents of the late Middle Ages: the contested authority of the church, the rising assertiveness of urban labor, and shifting dynastic fortunes. These developments influenced religious reform movements, later political centralization, and cultural transformations that helped set the stage for the early modern period.
Selected notable deaths (1378)
- Pope Gregory XI — whose death precipitated the papal elections and subsequent schism.
- Charles IV, Holy Roman Emperor — his passing led to succession by his son and affected imperial politics.