Matthias of Hunyad couldn't rest in peace after his death. Two powerful dynasty fought each other for the throne: Habsburg and Jagello. When you wanted to be Hungarian king you had to match for three conditions:
the
appropriate place /Basilica of Székesfehérvár - ancient capital of Hungary/,
the
appropriate priest to perform ceremony /archbishop of Esztergom and NOT archbishop of Kalocsa/ and
the
appropriate crown /Holy Crown of Hungary/.
This was the rule from middle of 13th century, so even Matthias had to repeat the ceremony in 1463, when he bought back the Holy Crown from Habsburg family due to they stole it in 1440 when Albert von Habsburg died, and his wife was pregnant whit later king László V. In exchange Matthias had to promise that after his death the throne will have the Habsburg family...
So the Habsburg army occupied Székesfehérvár for a year in 1491 to ensure the
place. The german mercenaries pillaged the tombs of kings in basilica during this time. We don't have to much data about this, and the city of Székesfehérvár conquered Ottoman Empire in 1543. In 1644 the basilica collapsed by an explosion of gunpowder, and everything disappeared forever. In 1848 was dig a well there, so they found an untouched tomb of king: Bela III. ruled Hungary 1172-1196. The symbol of double cross came from him, due to he was a hostige as a boy in Byzantium at court of Manuel emperor... We have nothing else from our kings, just a bunch of bones which mixed with a bones from a later cemetery from there. The bones are waiting for identify in the cellar of Hungarian National Museum.
When Napoleon Bonaparte conquered Vienna in 1806, he got Matthias death-shield as loot. Present day you can watch it in Museum of Les Invalides, Paris. The Hungarian State are trying get it back from the middle of 19th century, but so far just got a copy...
The death-shield of Matthias:
https://www.google.hu/search?q=mátyás+halotti+pajzsa&sa=X&biw=1920&bih=940&tbm=isch&source=iu&ictx=1&fir=ayvnfEJEofRu5M%3A%2CEyIXqTkcWGdk8M%2C_&usg=AI4_-kSdvbUtiCb0ZmcQFM9_JNnxWsAu5w&ved=2ahUKEwjNuNfcov7eAhUDCSwKHTz5CuwQ9QEwBHoECAYQBA#imgrc=ayvnfEJEofRu5M: