The palace of the Child King, also known as the Episcopal Palace, was built in the 12th century as part of the defences of the wall of Ávila, as the defence of each gate in the wall was entrusted to a palace.

The owner of the palace, the bishop, had to defend the cathedral gate. The palace was attached to the section of wall that runs between two gates, the former and the gate of San Vicente.

The palace is known as the palace of the Child King because the chronicles of the time tell us that the future King Alfonso XI was installed there, under the tutelage of Bishop Don Sancho, when he was transferred to Ávila to protect him until a regent guardian was appointed.

In 1775, the palace passed into the hands of the State when the Society of Jesus was suppressed. At that time it housed the public schools.

Over time it was divided up and various public bodies were established here: it currently houses the Post Office building and the State Public Library, which still conserves the palace's original Fruchel-style door, made of granite and topped by a coat of arms.

On the other hand, the rest of the palace was destroyed and in its place was built the current post office building, which dates from the 16th century and preserves part of the doorway, a corner window and the Sala de Sínodos (Synod Hall).