The Prague astronomical clock, or Prague Orloj, is a medieval astronomical clock attached to the Old Town Hall in Prague, the capital of the Czech Republic. The Orloj is mounted on the southern wall of the city’s Old Town Hall in the Old Town Square.
The clock mechanism has three main components – the astronomical dial, representing the position of the Sun and Moon in the sky and displaying various astronomical details; statues of various Catholic saints stand on either side of the clock; “The Walk of the Apostles,” an hourly show of moving Apostle figures and other sculptures, notably a figure of a skeleton that represents Death, striking the time; and a calendar dial with medallions representing the months. According to local legend, the city will suffer if the clock is neglected and its good operation is placed in jeopardy; a ghost, mounted on the clock, was supposed to nod its head in confirmation. According to the legend, the only hope was represented by a boy born on New Year’s night.
The late 19th and early 20th centuries were a transformative era for the Orloj. During this time, the clock evolved from a neglected, semi-functional relic into a celebrated national symbol of Czech cultural revival, right before facing near-destruction at the end of World War II.
By the mid-19th century, the clock was in poor condition and frequently stopped working. A massive, milestone restoration completed in 1866 completely modernized the clock’s appearance and mechanical reliability. The distinct wooden figures of the 12 Apostles that parade every hour were newly installed in the upper windows during this restoration. Celebrated Czech painter Josef Mánes was commissioned to create a brand-new, intricately painted lower calendar dial. His design featured 12 medallions depicting rural bohemian life matched to the signs of the zodiac. In 1865, a golden crowing rooster was added above the Apostle windows to signal the conclusion of the hourly mechanical show.
Following the 1866 restoration, Prague authorities realized that exposing Josef Mánes’ masterpiece painting to the elements would ruin it. The original Mánes calendar dial was carefully removed and moved to the Prague City Museum for safekeeping. It was replaced on the tower by an exact structural copy. After another round of reconstructions on the Old Town Hall facade, the golden rooster mechanism was fully finalized and played for the public for the first time on New Year’s Eve on December 31, 1882. The local Prague clockmaking company L. Hainz officially took over the maintenance and regular repair of the clock in the 1860s, a stewardship role they proudly maintained well into the 20th century.
The early 1900s brought massive technological adjustments and political upheaval to Prague, directly impacting how the clock told time. In 1912, the astronomical dial was modified to formally integrate Central European Time (German Civil Time). This update divided the standard day into 12 equal hours mapped to standard European timekeeping, though the complex internal gear adjustments meant it didn’t run perfectly until decades later. Following the collapse of the Austro-Hungarian Empire in 1918, Czechoslovakia declared its independence right in front of the clock tower. The clock was heavily embraced as a triumph of historic Czech engineering during this patriotic surge.
The darkest moment in the clock’s modern history occurred at the very end of WWII. On May 7–8, 1945, Nazi forces used anti-aircraft guns and incendiary shelling on the Old Town Square to suppress the Czech resistance broadcasting from the town hall. The building caught fire, the wooden Apostles and the calendar face burned to ashes, and the heavy medieval iron mechanism was severely warped by the extreme heat. The clock remained completely motionless and silent until a massive community-led restoration brought it back to life in 1948.
