Anchor year
642
Two conquests, one calendar year.
In 642 Muslim armies defeated a Sasanian force at Nahavand, a defeat from which the Sasanian state did not recover. In Egypt, Alexandria’s fall is commonly dated 641, with mopping-up into 642. Two shores. No arrow between them except the same expansion.
If 641 holds the city, what does 642 still hold?
Same year. Nothing more.
East
Nahavand
A Sasanian field army that does not re-form. The year is conventional. 641 holds Alexandria in many reconstructions.
West of that war
Egypt, still being taken
The fall of the city is often 641. 642 is completion. Two shores of the same expansion. No arrow except the calendar.
EAST
Nahavand
The Battle of Nahavand is conventionally dated 642. It broke remaining Sasanian field power. Yazdegerd III survived a few more years. The empire did not.
Before
Qadisiyya and the fall of Ctesiphon were already earlier in the conquest.
Why
The Sasanian state had been at war with Rome and then with the new Arabian armies. Exhaustion and fracture.
Who
Sasanian forces under Yazdegerd’s commanders; Rashidun armies of the early caliphate.
Yazdegerd III · the early Rashidun commanders
What
A field defeat that opened the Iranian plateau.
How
A pitched battle, then collapse of coordinated resistance.
The hinge
The hinge is a field army that does not re-form.
Where, and when
The Zagros, not the Tigris capital alone. 642, in most handbook chronologies.
642 · Nahavand, in the Zagros, Sasanian Iran
What they knew
The combatants knew they were fighting for a kingdom. They did not use our later name for the battle.
What they could not know
The later Persian literary memory of Nahavand as a world-gate.
Source object
Arabic conquest histories and later Persian memory
al-Tabari and others, written later. The year is conventional, not a surviving daybook.
The object survives.
First record
Later narrative histories. The date is a scholarly convention with some width.
After
Sasanian remnants; Yazdegerd killed in 651.
Later retelling
A civilizational turning packed into one toponym.
Limit
Exact day is not what we have. 642 is the conventional year.
What it does not prove
Does not make 42 a conquest number.
Why it entered
Included as independently major. Not as a rhyme with 1842’s treaty.
How we know
- 1. al-Tabari. History of the Prophets and Kings. Later narrative of the Battle of Nahavand, conventionally 642, and of the Egyptian conquest as a span with 641.
Method
independent firsthard
Not important to the existing work before this search.
The aperture
Independent-first political and military history. The neighbor 641 holds Alexandria’s fall in many reconstructions.
Regions checked
- Europe
- Middle East and North Africa
- East Asia
- South Asia
- Africa
- the Americas
- Central Asia
Included / excluded
- Included: Nahavand; Egyptian conquest as a span with 641
- Excluded: Alexandria as a locked 642 fall. Many reconstructions prefer 641. 642 is completion, not origin.
41 | 42 | 43
Same century. Same research threshold. Matched frames. Neither pane brighter except that the middle year is the selected aperture.
641
Neighbor
Death of Heraclius. Alexandria commonly dated this year. Neighbor is not quieter.
642
Aperture
Independent-first political and military history. The neighbor 641 holds Alexandria’s fall in many reconstructions.
643
Neighbor
Conquest continues in Iran and North Africa. Not empty.