The Other Batmen

This one will take some time to compile, but I think it will be worth it in the end.  During the Golden and Silver Ages, DC's writers and artists often created "other" Batmen.  Some were fakes and some were inspired by the Caped Crusader, but they all wore the mask.

The first inspired version of Batman to my knowledge lived in the year 3000.  His name was Brane, and the Earth he lived on had been conquered by the inhabitants of the planet Saturn.  He and his young pal Ricky come across a time capsule from the 1939 New York World's Fair.  Inside is film footage of Batman and Robin in action.  This inspires them:

They rout the Saturnians, and liberate their planet.  In the end, we learn that in the future, people contract their names by combining part of their first and last names.  Brane turns out to be the 29th century descendant of:

Brane returned in Batman #67, although in this story he was named Brane Taylor and he was from 3051, so perhaps he was a descendant of the other Brane.  His Robin has suffered a broken leg and he needs the 1951 model to help him out.  Dick agrees:

Brane returns the favor a few years later in Detective #216, when Bruce Wayne suffers a sprained arm and needs a stand-in as Batman.

Another inspired Batman is the superhero of Zur En Arrh, who appeared in Batman #113:

I particularly like his oddball version of Batman's costume.

One of my all-time favorite Batman stories is The Second Batman and Robin Team from Detective #220. Roger Bacon, a medieval scientist has discovered manuscripts documenting three of Batman and Robin's trips to the past (via Professor Nichols).  He reasons that they must be time travelers from the future (correct) and that all people in that future time must dress similarly (oops!).  He sends two young lads from his time into the future to learn the answer to his great question, which we learn here:

Unfortunately, as far as I know this was their only appearance.

Only two issues later, we learned of the Brotherhood of Batmen:

But it turns out to be a con; the idea is to get wealthy men to train to become one of the Brotherhood while also spending great sums to acquire their own Batmobile, Batplane, etc.  Terrific story.

Batman #62 included the story, The Batman of England. An English lord and his nephew decide to imitate our heroes.  However, the Knight and the Squire dress differently (in plate armor) and ride motorcycles, ludicrously carrying lances as well:

In the story, they are definitely a second-rate dynamic duo. Batman and Robin, pursuing some crooks to England, encounter them and they decide to collaborate, with the Squire joining Batman and Robin assisting the Knight.  But the Squire is too impetuous, and the Knight wants to stop in mid-chase for tea.  The story ends with them deciding to give up crime-fighting, although they did reappear in a World's Finest story called the League of Heroes a few years later, which featured superheroes from France, Italy and South America as well.

Another future Batman appeared in Batman #105.  Batman and Robin are surprised and concerned when a weird missile with a bat emblem shows up in the Batcave.  It turns out the missile is capable of transporting them through solid matter, making their jobs a lot easier.  The mystery is explained at the end:

There are, of course, a huge number of stories where Batman was imitated by some crook; for example this issue from the height of Batmania in 1966:

The telltale clue is that the costume Batman is wearing is the old outfit, without the yellow circle around the bat emblem on his chest.  In the story the Batman shown on the cover is a crook whom Batman had arrested before changing his costume.

Some others to be added: There's a three-issue series from the 1970s where Captain Stingaree is convinced that Batman is really triplets, and I also remember a rather silly GA story where there's an ersatz Dynamic Duo with Robin actually having a bald spot.  Any others?