For a compact connected
topological projective plane 𝒫, the following is shown: In the compact-open topology,
the automorphism group Σ of 𝒫 is a locally compact transformation group with
countable basis. If Σ is transitive on incident point-line pairs, or if dim𝒫≦ 16 and Σ
is point transitive, then 𝒫 is isomorphic to one of the four classical planes over an
associative or alternative division ring.