Mention of the peace between the Romans and the Muslims and then the war between them

It is narrated from Sayyiduna Dhu Mikhmar (may Allah be pleased with him) (who was a Companion of the Prophet (peace and blessings be upon him) and the nephew of the Negus) that he heard the Messenger of Allah (peace and blessings be upon him) say: "You will soon make a secure peace with the Romans, until you and they together fight a (common) enemy behind you. Then you will be granted victory and will take spoils, and then you will turn back until you camp in a meadow with hillocks (marj dhi tulul). Then a man from the Romans will (raise the cross and) say: The cross has prevailed. And a man from the Muslims will say (in reply): Rather, Allah has prevailed. They will dispute this between them. Then a Muslim will advance towards their cross, which will not be far from them, and break it. At this the Romans, enraged, will attack the one who broke their cross and kill him. Then the Muslims will rush to their weapons and they (too) will be killed, and Allah, the Mighty and Majestic, will honour that band of Muslims with martyrdom. Then the Romans will say to their king: We have spared you the might of the Arabs. Then they will betray (the truce) and gather for the great battle (al-malhamah); they will come to you under eighty (80) banners, with twelve thousand (soldiers) under each banner."
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs did not record it.

Khalid bin Ma'dan narrates from Jubayr bin Nufayr that he said: Take us to Sayyiduna Dhu Mikhmar (may Allah be pleased with him), the Companion of the Messenger of Allah (peace and blessings be upon him). He said: I heard the Messenger of Allah (peace and blessings be upon him) say: "The Romans will make a secure peace with you, then you and they together will fight an enemy; you will be granted victory, you will remain safe and you will be granted conquest. Then you will return to a meadow (marj), and there a man from among the Christians will raise the cross. At this a Muslim man will become angry, advance towards them and break the cross. At that point the Romans will become enraged and will gather for the great battle (al-malhamah)."
This hadith has a sahih (authentic) chain of narration, and it is more worthy (better) than the first narration.

Abdullah bin Bishr al-Ghanawi narrates from his father that he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "You will certainly conquer Constantinople; how excellent will be the commander who is its commander, and how excellent will be the army that is that army." Abdullah said: Then Maslamah bin Abd al-Malik called me and asked me about this hadith, so I narrated it to him, after which he launched a campaign against Constantinople.
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs did not record it.

It is narrated from Sayyiduna Abdullah bin Amr bin al-As (may Allah be pleased with them both) that he said: We were discussing the conquest of Constantinople and Rumiyah, that they would be conquered. Then Sayyiduna Abdullah bin Amr bin al-As sent for a chest and opened it, and then said: We were with the Messenger of Allah (peace and blessings be upon him), writing (hadith), when a man asked: O Messenger of Allah, which of the two cities will be conquered first? He (peace and blessings be upon him) said: "The city of Heraclius," meaning Constantinople.
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.