  The nucleon isovector electromagnetic form factors are calculated up to
next-to-next-to-leading order by combining relativistic chiral perturbation
theory (ChPT) of pion, nucleon, and $\Delta$(1232) with dispersion theory. We
specifically address the light-quark mass dependence of the form factors,
achieving a good description of recent Lattice QCD results over a range of $Q^2
< 0.6$ GeV$^2$ and $M_{\pi} < 350$ MeV. For the Dirac form factor, the
combination of ChPT and dispersion theory outperforms the pure dispersive and
pure ChPT descriptions. For the Pauli form factor, the combined calculation
leads to results comparable to the purely dispersive ones. The anomalous
magnetic moment and the Dirac and Pauli radii are extracted.
