Conquest of Constantinople; The Timeline

1444 Aug: Murad II abdicates in favor of Mehmed II and retires to Bursa

1446 Murad returns to throne. Mehmed as governor of Manisa
1451:

Death of Murad II, Mehmed II as sultan for second time.
Campaign against Ibrahim of Karaman.
Byzantines threaten to release Ottoman claimant Orhan
1452
14 February Venice agrees to send gunpowder and armour to Constantinople
15 April-31 August Ottomans build Rumeli Hisar, this encourages the Venetian Senate to prepare ships and send an embassy to discover the sultan's intentions.
28 August Mehmet II examines the walls of Constantinople then returns to Edirne
Autumn Mehmet II start assembling troops at Edirne; Byzantine emperor gathers grain and people into Constantinople
1 September Mehmet II arrives at Edirne, Hungarian gunfounder Urban transfers from Byzantine to Ottoman service and starts making giant cannon
in Edirne

October Mehmet II sends troops to raid Byzantine Morea; Cardinal Isidore arrives in Constantinople with 200 archers

November Concern about Rumeli Hisar leads Genoa to send Giovanni Giustiniani
Longo with men and ships to Constantinople

10 November Two Venetian merchant ships from the Black Sea pass Rumeli Hisar under fire

25 November Venetian ship from the Black Sea is sunk by gunfire from Rumeli Hisar

December:

Venetian galley from Trebizond under command of Giacomo Coco sails through the Bosphorus under fire; Venetian council in Constantinople agrees that no Venetian ships should leave without permission

12 December: Agreement to a Union of Churches

1453

January: Genoese galleys with 700 soldiers under Giovanni Giustiniani Longo arrive in Constantinople; Giustiniani made commander of land defenses

February

Ottoman advance guard under Karaca Bey storms Byzantine forts of Studius and Therapia

26 February Six ships escape from Golden Horn carrying 700 people

Spring Ottoman heavy guns brought from Edirne to face Constantinople; Karaca Bey captures several towns on Black Sea and Marmara coast.

March

Ottoman fleet assembles off Gallipoli and sails into Marmara; Anatolian troops cross Bosphorus via Rumeli Hisar

23 March Mehmet II leaves Edirne with palace regiments

Late March-early April Pope sends three Genoese ships to Constantinople with arms and provisions but these are storm-bound at Chios

2 April Chain drawn across Golden Horn; Mehmet II arrives in front of Constantinople

6 April Ottomans moves forward from assembly positions to within a mile of the walls of Constantinople; Byzantine defenders take up positions around walls

9 April First Ottoman naval attack on boom unsuccessful. Around this time, Ottoman troops take Therapia and Studios 11 April Erection of large mangonels in front of walls; giant Ottoman gun called Basiliske fires first shot

12 April Second Ottoman naval attack on boom unsuccessful

15 April Large Byzantine vessel and the three Genoese-Papal warships delayed by contrary winds, sail from Chios 16 April Ottoman fleet reinforced by large ships from northern Anatolia 17-18 April Ottoman surprise night attack driven back 18 April Ottoman attack on mesoteichion area; Ottoman fleet occupies Princes Islands 20 April Large Byzantine vessel and three Genoese-Papal warships break through Ottoman blockade into Constantinople 21 April Baltaoglu replaced as commander of the Ottoman fleet; cannon placed on northern side of Golden Horn; council of war near Diplokionion decides to continue the siege; large tower near St Romanos Gate collapses 22 April Ottomans complete slipway from Bosphorus and launch smaller warships into the Golden Horn 25-27 April Ottoman guns make further breaches in the walls 29 April Byzantines behead 260 Ottoman prisoners 30 April Ottoman guns make a breach at the St Romanos Gate

May Emperor collects more funds from churches to buy food for troops 2 May Great gun Basiliske returned to its original position 3 May Byzantines place guns on wall to attack Ottoman ships in Golden Horn; Emperor Constantine sends small ship beyond the Dardanelles to seek news of the Venetian relief fleet 5 May Ottoman high-angle mortar fires over Galata and sinks 'neutral' Genoese ship in Golden Horn 6 May Ottoman giant gun repaired; additional guns added to the St Romanos battery make another breach 7-8 May Ottoman night assault on breach at St Romanos Gate fails 9-13 May Venetian ships unload in Golden Horn 10 May Alvise Diedo given command of ships in harbour, Gabriele Trevisan takes spare crews to help defend Blachernac 11 May Loredan's ship leaves Venice 12-13 May Ottoman night assault penetrates Blachernae Palace, but is driven out 14 May Ottomans win full control of Golden Horn then move guns from Valley of the Springs to reinforce those bombarding Blachernac

16 May Guns from Valley of the Springs not effective against Blachernae so moved to main batteries in the Lycus Valley, Ottoman mines beneath Blachernae wall are discovered and defeated 16-17 May Ottoman fleet makes demonstration against boom, no shots fired

18-19 May Ottoman wooden towers are destroyed by kegs of gunpowder by night, others are then dismantled 19 May Ottomans complete construction of pontoon bridge across upper part of Golden Horn 21 May Ottoman ships unsuccessfully attack boom 23 May Small boat returns from reconnaissance with news that no relief fleet is in sight 24 May Lunar eclipse; Constantine refuses final surrender terms, Mehmet announces final assault within five days 25 May Byzantines destroy last of Ottoman mines 26 May Ottomans hear rumours of approaching European relief army; Mehmet II holds council with senior men 27 May Mehmet II tours the a heralds announce final attack army and 27-28 May Celebration fires lit at night in Ottoman camp because of forthcoming attack 28 May: Day of prayer and rest in Ottoman camp; Mehmet tours fronts; late afternoon Ottoman troops start filling in the fosse and bring cannon to close range

28-29 May Ottoman ships brought as close as possible to the sea walls at night 29 May Final Ottoman assault; Mehmet enters Constantinople early afternoon 30 May

Çandarli Halil replaced as Grand Vizier by Zaganos Pasha I June Mehmet II stops looting; Ottoman army is ordered back to camp Byzantine garrisons at Silivri and Epibatos surrender peacefully; Galata surrenders to Ottoman rule.

Courtesy:

The Fall of Constantinople: The Ottoman Conquest of Byzantium,

By D. NICOLLE J. HALDON S. TURNBULL