Third marriage of king Władysław II Jagiełło (Jogaila) was his only marriage from love, and shortest one too. Jogaila's decision to marry Elżbieta, widow of castellan Wincenty Granowski, who died in 1410, likely poisoned by Teutonic Knights, was heavy criticized. She was not of royal blood (although she was closely related to most powerful Polish families, her mother Jadwiga of Melsztyn was godmother of Jogaila, her uncle Spytek II of Melsztyn was voivode of Cracow) and her age makes it unlikely that she could give heirs to the king.
Traditionally it was assumed, that Elżbieta was born in 1372, so she'd be 45 years old at the time of her first marriage, although now that date is questioned, just like unbelievable story of her first two marriages, which were likely fictional, invented by Jan Długosz, who disliked Jagiellons. Likely Granowski was her only husband before Jogaila and at the time of her marriage with the King she was 35-37 years old, not 45 (still, by medieval standards that is quite late for marriage for a woman, but there are still chances for offspring).
So lets stick with younger Granowska theory and let's assume she is healthier (she died after 3 years of marriage, so her health likely started to deterioriate around the time she wed Jogaila) so she lives extra 15 years and gives birth to two royal sons (Władysław b. 1418, Kazimierz, b. 1420).
So what would be consequences? Queen Elizabeth was unpopular, in large part due to concerns, that she would not be able to give Jogaila a heir, ITTL these concerns are proved to be false. Jogaila would, obviously, try to secure throne for his sons. That should be a bit easier than IOTL with sons of Zofia Holszańska-Zbigniew Oleśnicki, who IOTL fought fiercely to deny Jogaila's sons hereditary rights to Polish throne, is not yet bishop of Cracow (bishop of Cracow was at the time politically the most influental member of Church hierarchy in Poland, more influental than archbishop of Gniezno, due to fact, that Cracow was capital) so is not important enough now to challenge the King. Jogaila's sons are also few years older than IOTL and related to powerful Melsztyński and Tarnowski families (which has good and bad sides). So how would Jogaila's struggle for his sons' succession end?
@krieger
Traditionally it was assumed, that Elżbieta was born in 1372, so she'd be 45 years old at the time of her first marriage, although now that date is questioned, just like unbelievable story of her first two marriages, which were likely fictional, invented by Jan Długosz, who disliked Jagiellons. Likely Granowski was her only husband before Jogaila and at the time of her marriage with the King she was 35-37 years old, not 45 (still, by medieval standards that is quite late for marriage for a woman, but there are still chances for offspring).
So lets stick with younger Granowska theory and let's assume she is healthier (she died after 3 years of marriage, so her health likely started to deterioriate around the time she wed Jogaila) so she lives extra 15 years and gives birth to two royal sons (Władysław b. 1418, Kazimierz, b. 1420).
So what would be consequences? Queen Elizabeth was unpopular, in large part due to concerns, that she would not be able to give Jogaila a heir, ITTL these concerns are proved to be false. Jogaila would, obviously, try to secure throne for his sons. That should be a bit easier than IOTL with sons of Zofia Holszańska-Zbigniew Oleśnicki, who IOTL fought fiercely to deny Jogaila's sons hereditary rights to Polish throne, is not yet bishop of Cracow (bishop of Cracow was at the time politically the most influental member of Church hierarchy in Poland, more influental than archbishop of Gniezno, due to fact, that Cracow was capital) so is not important enough now to challenge the King. Jogaila's sons are also few years older than IOTL and related to powerful Melsztyński and Tarnowski families (which has good and bad sides). So how would Jogaila's struggle for his sons' succession end?
@krieger