In magnetic materials, the Pauli exclusion principle typically drives anti-alignment between
electron spins on neighbouring species resulting in antiferromagnetic behaviour.
Ferromagnetism exhibiting spontaneous spin alignment is a fairly rare behaviour, but once
materialized is often associated with itinerant electrons in metals. Here we predict and
rationalize robust ferromagnetism in an insulating oxide perovskite structure based on the
popular titanate series. In half-doped layered titanates, the combination of Jahn–Teller and
oxygen breathing motions opens a band gap and creates an unusual charge and orbital
ordering of the Ti d electrons. It is argued that this intriguingly intricate electronic network
favours the elusive inter-site ferromagnetic (FM) ordering, on the basis of intra-site Hund’s
rules. Finally, we find that the layered oxides are also ferroelectric with a spontaneous
polarization approaching that of BaTiO3. The concepts are general and design principles of the
technologically desirable FM ferroelectric multiferroics are presented.