It's the last of the original Planet of the Apes films. Number five is Battle for the Planet of the Apes from 1973, directed by J. Lee Thompson.
It's ten years since the slave uprising in the last film and a raggedy group of apes and humans are trying to scratch out a living in the aftermath of a nuclear war. They are led by Caesar (Roddy McDowell again) who has won the war and now has to win the peace. He's got dissent in his own ranks coming from the gorillas led by General Aldo, and he has to deal with attacks from a group of human survivors living under the ruins of a radioactive city. This bunch of scarred, gun crazy loons are well on their way to transforming into the mutants who we saw in the second movie. So at least there is a suggestion of building the continuity of the whole time loop that links all the films.
This is probably the first Apes film I saw when I snuck into a cinema under-age in 1973 or 1974. But it was the film I couldn't remember anything about at all. So it all came as a complete surprise to me. Caesar has now moved from the revolutionary we saw in Conquest and here he more resembles Nelson Mandela trying to build a peaceful community after a terrible war and a reversal of fortunes for the oppressed apes and their human masters. Of course we know the peace won't last. The clue is the word Battle in the title. So soon he has pissed off the mutating human neighbours and then there are plenty of guns and explosions, including one shot of an exploding tree that they liked so much they kept using it over and over again.
Style notes: in the ten years since the last film the apes have all adopted the familiar coloured outfits that we remember from the original film. The mutants have started to wear their skull caps. And the rest of humanity get to wear rather grubby, grey uniforms. Clearly the apes get all of the soap in this post-apocalyptic society.
It's a short film with not a lot to say either for or against it. However it is very nice to see Austin Stoker who played the police lieutenant in the brilliant Assault on Precinct 13.
So if I had to rank the ape films in order of greatness then the original is still the best and then it goes Conquest, Escape, Battle and Beneath in diminishing order.
Next up, the apes documentary and then it will be time for Marky Mark