9 historical mysteries that may never be solved

In the dark streets of Whitechapel in 1888, a brutal killer known as Jack the Ripper terrorised London.

The murderer claimed the lives of at least five women and mutilated their bodies in ways that shocked investigators and the public letters signed with the Ripper’s name taunted the authorities, though handwriting analysis has never confirmed their origin.

Over time, suspects have ranged from Aaron Kosminski, a Polish barber with a history of mental illness, to Sir William Gull, physician to Queen Victoria.

Forensic efforts that used modern DNA analysis failed to provide a clear match, in part due to the decay and mixing of evidence over the past century.

A 2014 mitochondrial DNA study linked a shawl said to belong to Catherine Eddowes with Kosminski, but critics have dismissed the results as unreliable because their origin was doubtful and custody records were missing.  

According to biblical tradition, the Ark of the Covenant was a gold-covered chest that had held the Ten Commandments.

However, during the Babylonian sack of Jerusalem in 586 BC, all traces of the Ark vanished.

Some accounts claimed it had been hidden beneath the ruins of the destroyed temple, while others stated it had been transported to Ethiopia, where local clergy in Axum have long claimed to guard it in privacy.

The Church of Our Lady Mary of Zion is said to house the relic, though only a single guardian is allowed access.

Without direct examination of the relic and lacking physical evidence of its fate, the Ark has remained at the centre of religious and academic debate.

The text 2 Maccabees 2:4-8, which is considered deuterocanonical in some Christian traditions, also suggests that the prophet Jeremiah hid the Ark in a cave before the destruction.  

In early second-century Roman Britain, the Legio IX Hispana had served in Britain since the early stages of Roman occupation and had earned distinction in earlier conflicts.

After AD 120, it no longer appeared in British inscriptions or official records. Some believe that the legion was destroyed during an uprising in the north, possibly led by Pictish tribes.

However, later inscriptions discovered at Nijmegen suggest that elements of the legion may have been transferred to the Rhine frontier and continued to exist into the mid-2nd century. T

he last known inscription confirming the legion’s presence in Britain comes from Eboracum (modern-day York) around AD 108.

Some scholars have proposed that the construction of Hadrian's Wall may have been prompted by a major uprising that seriously weakened or destroyed the unit.  

In the final days of Ptolemaic Egypt, Cleopatra VII and Mark Antony chose suicide over surrender following their defeat by Octavian in 30 BC.

Ancient authors, including Plutarch, claimed they were buried together in a tomb located near Alexandria’s royal area.

Since the city suffered repeated earthquakes and tsunamis in the centuries that followed, much of ancient Alexandria has sunk beneath the Mediterranean.

Despite modern searches along the coast and in the temple complex at Taposiris Magna, no tomb or funerary inscription has confirmed the location of their burial site.

The archaeologist Kathleen Martinez has led extensive excavations at Taposiris Magna since the early 2000s, and this work revealed Ptolemaic-era artefacts which some scholars interpret as evidence that a royal tomb could lie nearby.

However, most Egyptologists express doubt about any direct connection between the site and Cleopatra.  

In 1908, Italian archaeologist Luigi Pernier discovered a clay disc in the ruins of the Minoan palace at Phaistos.

Covered in a spiral of stamped symbols, the Phaistos Disc is still unreadable.

Unlike other ancient scripts, the disc’s writing has no known parallels, making language comparisons impossible.

Some suggest the symbols stand for a form of proto-writing. Others claim the disc is a ritual object or have speculated it could be a forgery, though most scholars consider it genuine due to its archaeological context and the credibility of its discoverer.

The disc contains 242 symbols grouped into 61 segments and appears to be the earliest known use of movable type stamping.

Since no similar examples have been found in Minoan ruins or collections, attempts to decipher its message have relied purely on guesswork.  

During the Bronze Age, the Indus Valley Civilisation flourished in what is now Pakistan and northwest India.

Its cities, including Mohenjo-daro and Harappa, displayed advanced planning, and they featured uniform construction alongside detailed drainage systems.

Sometime after 1900 BC, the civilisation began to decline. Soil layers do not show clear signs of warfare or invasion.

Scholars have instead pointed to environmental changes, including river shifts and repeated droughts.

Climate data from climate science supports this theory, suggesting a weakening monsoon pattern.

Inscriptions in the Indus script are unreadable, which prevents historians from hearing the voices of those who witnessed the collapse.

The lack of bilingual texts has made decipherment of the script particularly difficult.  

On a remote Pacific island, the Rapa Nui carved nearly 900 giant stone statues, called Moai, between AD 1250 and 1500.

Quarried from volcanic rock, the statues were transported across uneven terrain to ceremonial platforms.

Oral histories claimed the statues “walked,” and some experimental archaeologists have replicated transport methods using ropes and coordinated teams.

Scholars such as Terry Hunt and Carl Lipo have shown how rocking the statues upright with ropes could explain the movement without wheels or animals.

Despite those efforts, scholars are divided over how such massive figures could have been moved, with some still supporting traditional sled or roller methods.

The island’s deforestation during the same period has also prompted questions about whether the statue construction contributed to resource depletion.

Some researchers believe the introduction of Polynesian rats, which consumed palm seeds, may have sped ecosystem collapse.  

In 1587, English settlers attempted to establish a colony on Roanoke Island in what is now North Carolina.

When John White, the colony’s governor, returned from a delayed supply trip in 1590, he found the site abandoned.

The word “Croatoan” had been carved into a post, but no signs of struggle or flight could be found.

Some believe the settlers assimilated into neighbouring Indigenous communities.

Others have argued that starvation eroded their supplies, disease afflicted the settlers and internal conflict undermined their cohesion, leading to the group’s disappearance.

White’s return had been delayed by the Anglo-Spanish War, which had prevented him from securing a ship earlier.

Archaeologists have uncovered European artefacts in areas inhabited by the Croatoan people, though none have been definitively linked to the colonists.

Since no bodies, graves, or personal items from the settlers have been confirmed, the colony’s fate is unknown.  

In the early 20th century, book dealer Wilfrid Voynich purchased a manuscript filled with illustrations of unidentified plants, bathing figures, and sky charts, all accompanied by text written in an unknown script.

Radiocarbon dating has placed the creation of the Voynich Manuscript in the early 1400s.

Despite the efforts of cryptographers, linguists, and historians, no one has decoded the text.

Some argue it uses an invented language or cipher, and others suggest it may be a crafted medieval hoax intended to fool contemporary collectors or patrons.

The manuscript is now housed at Yale University’s Beinecke Rare Book & Manuscript Library.

Researchers at the University of Arizona dated the vellum to between 1404 and 1438.

In the absence of any similar documents, the manuscript’s origin and purpose are matters of debate.