The Prophet (ﷺ) wrote to the Kings of the Kuffar, inviting them to Islam

It has been narrated on the authority of Anas that the Prophet (ﷺ) of Allah (ﷺ) wrote to Chosroes (King of Persia), Caesar (Emperor of Rome), Negus (King of Abyssinia) and every (other) despot inviting them to Allah, the Exalted. And this Negus was not the one for whom the Messenger of Allah (ﷺ) had said the funeral prayers.

حَدَّثَنِي يُوسُفُ بْنُ حَمَّادٍ الْمَعْنِيُّ، حَدَّثَنَا عَبْدُ الأَعْلَى، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، أَنَّ نَبِيَّ اللَّهِ صلى الله عليه وسلم كَتَبَ إِلَى كِسْرَى وَإِلَى قَيْصَرَ وَإِلَى النَّجَاشِيِّ وَإِلَى كُلِّ جَبَّارٍ يَدْعُوهُمْ إِلَى اللَّهِ تَعَالَى وَلَيْسَ بِالنَّجَاشِيِّ الَّذِي صَلَّى عَلَيْهِ النَّبِيُّ صلى الله عليه وسلم ‏.‏

The tradition has been narrated on the authority of Anas b. Malik (the same narrator) through a different chain of transmitters, but this version does not mention:

" And he was not the Negus for whom the Prophet (ﷺ) had said the funeral prayers."

وَحَدَّثَنَاهُ مُحَمَّدُ بْنُ عَبْدِ اللَّهِ الرُّزِّيُّ، حَدَّثَنَا عَبْدُ الْوَهَّابِ بْنُ عَطَاءٍ، عَنْ سَعِيدٍ، عَنْ قَتَادَةَ، حَدَّثَنَا أَنَسُ بْنُ مَالِكٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم ‏.‏ بِمِثْلِهِ وَلَمْ يَقُلْ وَلَيْسَ بِالنَّجَاشِي الَّذِي صَلَّى عَلَيْهِ النَّبِيُّ صلى الله عليه وسلم ‏.‏

It has been narrated on the authority of the same narrator through another chain of transmitters with the same difference in the wording.

وَحَدَّثَنِيهِ نَصْرُ بْنُ عَلِيٍّ الْجَهْضَمِيُّ، أَخْبَرَنِي أَبِي، حَدَّثَنِي خَالِدُ بْنُ قَيْسٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، وَلَمْ يَذْكُرْ وَلَيْسَ بِالنَّجَاشِيِّ الَّذِي صَلَّى عَلَيْهِ النَّبِيُّ صلى الله عليه وسلم ‏.‏