List of former national capitals

Columns: Old capital city | Country | Today a part of | From | Until | Change , reason
Firouzabad , Ctesiphon , Damghan | Sassanid Empire | Iran | 224 | 637 | fell in Islamic conquest of Persia | Nishapur | Tahirid dynasty | Iran | 821 | 873 | conquered by Saffarid dynasty | Zaranj , Amol | Saffarid dynasty , Alavids | Iran | 861 | 900 | conquered by Samanid | Bukhara , Balkh , Samarkand , Herat | Samanid dynasty | Iran | 875 | 999 | conquered by Ghaznavids | Ghazni | Ghaznavids , Ghurids | Iran | 963 | 1212 | conquered by Seljuq dynasty | Nishapur , Rey , Konye-Urgench | Seljuq dynasty , Khwarezmid dynasty | Iran | 1037 | 1231 | conquered by Ilkhanate

Example questions:
What is the capital city of this southwest Asian nation that today covers the ancient city whose name was recorded by Carsten Niebuhr ? | When did this southwest asian empire collapse that once had Qal'at Sherqat as the capital city ? | What is the population of this country in southwest asia where the largest city in the world until 610 BC is located ? | How far is this ancient city of the kingdom in southwest Asia spanning 5.5 million square kilometers located from the city of Shiraz ?

Answers:
Baghdad | between 612 BC and 609 BC | 38 million | 60 kilometres