[4] While Vlad was eventually released to take his place on the Wallachian throne in 1448 after his father was killed by John Hunyadi, Radu converted to Islam and was allowed into the Ottoman imperial court.

[5] In November 1447, John Hunyadi launched an attack against Wallachia due to its alliance with the Ottomans by the treaties signed by Vlad II Dracul and his duplicity in Varna Campaign (1444).

Radu's father fled, but Mircea II was captured by boyars from Târgoviște and was blinded with a red-hot poker before being buried alive.

Vlad III waged a guerrilla campaign against the Ottoman forces commanded by the Grand Vizier Mahmud Pasha in May 1462, pursuing them in their retreat as far as the Danube.

After Mehmed II suffered losses from The Night Attack, Radu and his loyalists campaigned on the Danubian plains for support to replace his brother.

Radu sent envoys to the Saxon cities hardest hit by Vlad III, tempting them with old-fashioned advantageous trade regulations and vouching for the sanctity of their families.

Radu chased Vlad III to his castle north of Curtea de Argeș and, finally, out of Romania itself, which was incorporated under Ottoman control.

[7] Meanwhile, his brother Vlad III, due to his harsh policies towards the boyars (whose power struggles he blamed for the state of the realm), was betrayed by them.

Soon after, the Janissary under his command began attacks and raids on Vlad III's mountain stronghold on the Argeș River, Poenari Castle.

In 7 March 1471, Radu fought the Battle of Soci against Stephen III, his future son-in-law, for possession of Chilia (now Kiliya in Ukraine).