Isterik Reference Timeline
Istvan born (1358)
1st Hungarian–Ottoman War (1366-7) - Istvan 8-9
Erik born (1373) - Istvan 15
2nd Hungarian–Ottoman War (1375-7) - Istvan 17-19, Erik 2-4
First Moravian Margrave War (1381 - September 1382) - Istvan 23-24, Erik 8-9
Battle of Kosovo (15 June, 1389) - Istvan 31, Erik 16 [There's nothing in the game to suggest they would have been present for this, but it's a notable date]
Second Margrave War (1393 - May 1396) - Istvan 35-38, Erik 20-23
3rd Hungarian–Ottoman War (1389-96) - Istvan 31-38, Erik 16-23
Battle of Nicopolis (25 September, 1396) - Istvan 38, Erik 23
Third Margrave War (1398-1400) - Istvan 40-42, Erik 25-27
Sack of Skalitz (1403) - Istvan 45, Erik 30
Moravian Margrave Wars end (1405) - Erik 32
Istvan was probably orphaned during the 1st Hungarian–Ottoman War (1366-7) at the age of 8-9. The Moravian Margrave Wars began in 1381 when he was 23 and Erik 8; Erik could have been orphaned at any time after that. At the Battle of Nicopolis, Istvan was 38 and Erik 23.
This timeline is based on the dev notes where their ages were specified, which aren't exactly accurate to their characters in the final game (e.g. Istvan doesn't have a scarred face; Erik isn't gingery-blond), but it makes sense to me.
Edit: Someone pointed out that Erik in the final form that we see in the games is supposed to be the same age as Henry and Hans, not 30 as the dev notes suggest. I always struggle to see them as 20-year-olds because the actors are so obviously men in their 30s and 40s lol but that means Erik was born in 1383. He would probably have been orphaned during the Second Margrave War, aged 10-13.
