The Battle of the Trench: the siege of Medina

The confederates gather

Two years after failing to follow up their victory at Uhud, the Quraysh of Mecca assembled the largest force Arabia had seen against Medina. The driving organisers were leaders of the Banu Nadir, a Jewish tribe expelled from Medina in 625 CE after the breakdown of relations under the Constitution of Medina; from exile in Khaybar they toured the tribes promising alliances and payment. The result was a coalition — the Ahzab, "the confederates", which gives the battle its other name — of the Quraysh under Abu Sufyan, the powerful Ghatafan of Najd, and allied clans, put by the sources at around 10,000 men. The defenders of Medina numbered roughly 3,000.

Salman's idea: dig

Medina's geography did most of the defensive work by itself. Dense date-palm plantations and fortified houses covered the south, and fields of broken black basalt — the harrat — flanked the city east and west, terrain no cavalry could cross in order. The city's one open approach was from the north. Tradition credits Salman al-Farsi, a Persian companion, with proposing a tactic familiar in Persia but unknown in Arabia: cut a trench across that northern gap, wide and deep enough that horses could not leap it.

With the coalition on the march, the Muslims dug for days in cold weather and on short rations — the Prophet Muhammad working among them — running the ditch across the open ground north of the city, anchored on the small mountain of Sala. Hadith literature preserves vivid scenes from the digging: the work songs, the shared hunger, and the Prophet breaking a boulder the others could not shift.

A siege of nerves

When the confederates arrived — in Dhu al-Qa'dah 5 AH, early 627 CE — the trench stopped them cold. Cavalry, their decisive arm, was useless against it; a few riders who attempted the narrowest point were driven back, and the celebrated Meccan champion Amr ibn Abd Wudd was killed in single combat by Ali ibn Abi Talib. The battle settled into blockade: archery exchanges across the ditch, probing attacks, and mounting strain inside the city, which the Qur'an describes in Surah al-Ahzab (33:10–11) — eyes swerving, hearts in throats.

The crisis deepened when the Banu Qurayza, the last major Jewish tribe inside Medina, were persuaded by the Nadir exile Huyayy ibn Akhtab to abandon their pact with the Muslims, opening the threat of a second front from the south-east. The counterstroke was diplomatic. Nu'aym ibn Mas'ud of Ghatafan, a recent and still-secret convert to Islam, moved between Qurayza and the confederates sowing mutual suspicion — each side came to believe the other would betray it — and the coalition's cohesion dissolved. After roughly two to four weeks (the sources give varying lengths, with about 27 days often cited), supplies failing and a bitterly cold night wind wrecking the besiegers' camp, Abu Sufyan raised the siege. Total deaths on both sides over the whole affair were remarkably few — the sources count them in single figures to a dozen or so.

Aftermath

The withdrawal broke the Meccan cause: the Quraysh never mounted another campaign against Medina, and within three years the city that could not be taken had taken Mecca. The immediate aftermath was grimmer. The Banu Qurayza were besieged in their forts for their breach of the pact and surrendered; by the judgment of Sa'd ibn Mu'adh, chief of their former allies the Aws, the tribe's fighting men were executed and the remainder taken captive — an episode reported by the early sources and discussed extensively, and sometimes critically re-examined, by later scholarship.

The battle at a glance