[3] In turn, the emperor appointed Conrad Duke of Franconia and both brothers German regents when he left for his second Italian campaign in 1116, who put down a revolt by Archbishop Adalbert of Mainz.

[3] About 1120 Frederick married Judith, a daughter of Duke Henry IX of Bavaria and member of the powerful House of Welf.

Frederick II, Henry's nephew, stood for election as King of the Romans with the support of his younger brother Conrad and several princely houses.

However, he lost in the tumultuous round of elections,[citation needed] led by Archbishop Adalbert of Mainz, to the Saxon duke Lothair II.

Frederick at first rendered homage to the new king, however, he refused the feudal oath and insisted on the inheritance of the Salian family estates along the Middle Rhine.

In December 1127 Conrad declared himself King of the Romans, while the next year Duke Frederick II occupied the Salian city of Speyer.