Hezekiah's Tunnel and the Siloam Inscription in Jerusalem

Hezekiah’s Tunnel is a rock-cut water channel beneath the City of David, the oldest part of Jerusalem, carrying water from the Gihon Spring to the Pool of Siloam. It is traditionally linked to King Hezekiah of Judah, who prepared the city for an Assyrian attack around 701 BC. A Hebrew inscription carved inside, the Siloam inscription, describes the moment when two teams of diggers met underground, and it is one of the most important texts surviving from the kingdom of Judah.

Background: water and war

Ancient Jerusalem stood on a narrow ridge, and its only perennial water source, the Gihon Spring, lay in the Kidron Valley at the foot of the eastern slope, outside or at the edge of the city walls. In a siege, control of the spring could decide the city’s fate.

In the late 8th century BC the Assyrian Empire was expanding into the region. It destroyed the northern Kingdom of Israel after the fall of Samaria around 722 BC. When Hezekiah joined a revolt against Assyria after 705 BC, he expected retaliation, and it came in 701 BC with Sennacherib’s campaign and the siege of Lachish.

The Bible credits Hezekiah with securing Jerusalem’s water. 2 Kings 20:20 says he “made the pool and the conduit, and brought water into the city”, and 2 Chronicles 32:30 says he stopped the upper outlet of the Gihon and directed the water down to the west side of the City of David.

The tunnel

The tunnel winds for about 533 m through the limestone, although the straight-line distance between its two ends is only about 320 m. Its height varies from roughly 1.1 m to 5 m, and its floor drops only about 30 cm along its whole length, a very gentle gradient that kept the water flowing.

Why the tunnel follows an S-shaped course is still debated. Some scholars think the diggers followed natural fissures in the rock, which may have guided them and carried sound; others suggest they avoided royal tombs or simply corrected their direction as they went. Marks in the walls show that two teams started from opposite ends and met near the middle, where the passage zigzags as they adjusted to find each other.

The Siloam inscription

In 1880 a boy wading in the tunnel noticed letters carved in the wall about 6 m from the Siloam end. The German architect and archaeologist Conrad Schick reported the discovery, and scholars soon deciphered the text. In 1890 or 1891 the inscription was illegally cut out of the wall and broken; Ottoman authorities recovered the pieces and sent them to the imperial museum in Constantinople, now the Istanbul Archaeology Museums.

The text has six lines in the Paleo-Hebrew script, a form of the alphabet derived from Phoenician writing. It tells how the hewers swung their picks towards each other and, when only three cubits remained, heard a voice calling through the rock. On the day of the breakthrough they struck pick against pick, and the water flowed from the spring to the pool for 1,200 cubits. The height of the rock above their heads was 100 cubits.

Unusually for a monumental text, the inscription names no king and no god. It celebrates the work itself, and it was placed inside the tunnel rather than in a public place. It is one of the longest Hebrew inscriptions from the period of the First Temple.

Dating and debate

Most scholars have dated the tunnel and its inscription to Hezekiah’s reign on the basis of the biblical texts and the style of the letters. In 2003 a team published uranium-thorium dates from cave deposits and radiocarbon dates from plant remains in the plaster, which pointed to around 700 BC and supported the traditional view.

Some archaeologists who have worked in the City of David have argued that parts of the water system, or even the tunnel itself, may be older, perhaps from the late 9th or early 8th century BC. The question remains open, but the link with Hezekiah is still the most widely accepted view.

Exploration and legacy

The American scholar Edward Robinson explored and measured the tunnel in 1838, and the British engineer Charles Warren surveyed it in 1867. Today it is part of the City of David archaeological park, and visitors can wade through it by torchlight in water that still flows from the Gihon Spring.

The Siloam inscription remains in Istanbul, while a replica is displayed in Jerusalem. Its ownership has occasionally been raised in diplomatic discussions between Israel and Turkey.

Timeline

• c. 715-686 BC: Reign of Hezekiah, king of Judah, in a widely used chronology (others place it about 727-698 BC).
• 705 BC: Death of Sargon II; Hezekiah rebels against Assyria.
• 701 BC: Sennacherib invades Judah; the tunnel is generally thought to be finished by now.
• 1838: Edward Robinson explores and measures the tunnel.
• 1880: The Siloam inscription is discovered by a boy in the tunnel.
• 1890-1891: The inscription is cut out of the wall and later taken to Constantinople.
• 2003: Radiometric dating supports a date of around 700 BC.

Why it matters

Hezekiah’s Tunnel is a remarkable feat of Iron Age engineering, cut by hand without modern surveying tools. Its inscription offers a rare voice of ordinary workers from ancient Judah and a direct material link to events described in the Bible, from a period when Jerusalem was still the capital of an independent kingdom.