What if Boleslaw the Wrymouth does not remarry and his son the OTL Wladyslaw the Exhile was his only son, what will happen to Poland?
Poland remains united, of course - no fragmentation. No internal conflicts, since Władysław has no serious competition. IOTL most of his problems were caused by his conflicts with brothers - but now he is a single child. He has good relations with Bohemia, HRE and Ruthenia. He has 2 sons, so succession is safe. With some luck Poland leaves in peace for almost 100 years, until the Mongols come (if they are not butterflied away). After that, who knows?
And how Wladyslaw divides Poland between sons?
If he died in 1159, as in OTL, the some kind of civil war will begin in 1160s?
And Valdemar I of Denmark butterflied away, at least.
It's seems, if Boleslaw doesn't remarry, it changes the history not only Poland.
Remember, it was 12th century, even if he had 5 sons he can't be sure that any of them will outlive him. And some degree of disintegration is rather inevitable, maybe not to OTL degree but still.I think he will stop consummating the marriage after having two sons in order to avoid the division of Poland or a fratricidal war from happening.
I think the sons of Wladyslaw can have the Capetians as their model.Remember, it was 12th century, even if he had 5 sons he can't be sure that any of them will outlive him. And some degree of disintegration is rather inevitable, maybe not to OTL degree but still.