Ottokar I of the HRE (Chaos)

The life of OTL Otakar Przemysl took a different way when in 1247, his elder brother didn't die and also had a son, later king Wenzel / Venceslaus / with his wife Gertrude, daughter of the last Babenberger duke of . Thus, when their father died in 1253, Vladislav inherited Bohemia and Austria. The ambitious Otakar insisted however that he got at least, and thus the Przemyslid realms were split. In 1254, Austria was further enlarged when was split with under .
One year later however, in 1255 Vladislav would die already, and now Otakar had the opportunity to act as regent for his nephew. He immediately tried to improve the situation, waged war against Hungary, but was defeated. In the next few years, he had to suppress Bohemian and Austrian nobles discontent with his rule. He became a bit more humble and pragmatic in the future, looked for new allies, made peace with the Bavarian dukes and married Sophie of Wittelsbach. 1261, his son and heir Heinrich was born.
At several opportunities, like 1257, he went to , helped to suppress a big uprising of the Prussians. The named (OTL Königsberg) after him.
He had his greatest success in 1268, when childless duke and Carniole made a secret contract with him, that the latter one would inherit the former's lands after his death (which would come next year).
After the death of Roman king Richard and the forced abdication of Alfonso in 1273, had to elect a new king. Among the candidates were the French king and Otakar Moravia and . ITTL, he wasn't absent from the election and could influence it better. The other princes also considered him less dangerous, since his nephew now reigned independent from him. Since Vaclav II, elector of Bohemia, voted for him, the Upper Bavarian duke and the three archbishops supported him too, he was elected king Ottokar I of the HRE.
In 1275, king Ottokar lead the Empire against Hungary, defeated the new king and got Styria back for the HRE. Styria was divided again: Western Styria became part of Austria (thus connecting the Przemyslids' possessions), the rest (two thirds) became (Upper) Bavarian.
1286, king Otakar decided to go on a crusade against the Muslims, after the pope had promised him to crown him Holy Roman Emperor. But while he always fought valiantly against the pagans in Prussia and , which gave him the epiphet of "the Iron duke", he was not so lucky now. Having reached with his army, he died. The crusade was cancelled, and the chance to rekindle actual interest in it was lost. 
His lands went to his son .