We have a mainecoon male neutered cat.  We have lived in our quiet little terrace for 8 yrs now and he has been able to get outside since we moved here(He's 10 yrs old).  About a year ago, some neighbours got a male kitten and ever since then, him and Axel have been fighting like.....well, cats!lol.  They have 4 gardens between the black cats and ours but Axel has always snoozed under my next-door neighbours hedge during the summer so he counts that garden as his, I imagine.  This black cat knows no boundaries! He jumps up to our livingroom window most nights, which sends Axel mad.  He jumps at the window growling like mad. And he'll sit on the doorstep waiting for Axel to come out(which I don't allow) but I have now started a nasty habit of letting the dog out.  She adores Axel but hates other cats so she soon see's him off.  And I'm not evil.  She couldn't catch him if I gave her 10 mins head start!!lol.

What am I going to do? Short of catnapping and tossing him out miles away....I do like the black cat, I just want him to leave Axel alone! 
Of course, Axel won't stay in and uses all his intellect to suss out new and ingenuis way of escaping into the big outdoors.  And, he absolutely refuses to use a littertray now after so many years.
My main worry is, he is getting quite badly injured being an older cat against a young spritely thing.  He's had 2 courses of AB's in December alone due to bites and has a big hole in his head atm due to his previous fight, which I am nursing him through.  It's just getting far to regular.
Any ideas?

Unfortunately his territory has been invaded by a younger and more territorial cat, it happens a lot, a peaceful neighbourhood with cats that don't bother each other can soon be turned into a war zone. What can you do about it? Nothing hun......... been there, done it, had the vet bills, to show for it.

I was at my wits end, luckily the owner moved, my only reprieve from the daily cat fights, I spent my days with a garden brush running up and down my drive like a mad woman. You can't make anyone keep their cat in, or even keep them on their own territory.

The only legal deterrent is a water pistol but you would have to be on guard 24/7 no-one can do that, you can protect your back garden with rollers/plastic spikes on the top of your fence/wall, but you're probably like I was and your cat is being attacked from the front where you can not put up any deterrents to stop the cat wishing to attack yours. :-(

You're left with no choice other than keeping your own cat safe, you may need to get him to use your back garden alone now, it's annoying and a pain in the bum, this particular cat for me, even with a dog in the house who also would see  him off, an angry owner who would shoo him away at every opportunity and who saw the back end of my garden brush many times would still walk as bold as brass into my house when doors and windows were open to fight my cat, nothing stopped it, and yes I had images of wringing its neck, if it had stayed I would have no doubt needed to go to the expense of getting a cat pen just to keep my boy safe, it was the only option left.

In turn I guess your MC's life will have to change to keep him safe, get window protecters to stop him getting out, not fair I know, when he has done nothing wrong, but unfortunately the thugs of this life always cause us to change ours. :-(

Really feel for you.

Just as a side note - I guess as I did you have had words with the neighbour, I kept threatening vet bills, even though it would not have stood up, but you could suggest neutering if it has not been done already, although it may also not make any difference some cats are just very territorial. :-(

I've not mentioned it to the neighbour yet as I am perfectly aware that their is little they NEED to do and I don't really want to fall out with anyone over cats!!lol.  I think I will approach them and try and work out a schedule so they don't need to meet each other.  Think my old boy is a bit intimadated tbh as he is staying in a bit more these days which is fine by me.
PS  Tempting thing is, that cat is very curious and has sneaked into our car a few times while cleaning it out(4dogs and 4 kids = car cleaned A LOT) and I'm really not liking him at the minute!! If I weren't such a lover of cats.......but it's not his fault(I keep telling myself!lol)

Very difficult I had alittle of this for a while but fortunately all seems calm atm My boss has a similar problem with her cat being regularly attacked. A friend of mine has secured her back garden with rollers on the fence top designed for exactly that pupose. her cat only ever goes out the back and know one gets in.Expensive but effective. Otherwise a run on the back of the house, again expensive but I guess you will save in vets bills and stress

I would seriously build a fully enclosed run. You have no way of knowing what your cat is getting infected with -Feline Immunodeficiency Virus for instance is spread via bites, and the infected cat can appear healthy for years. It's russian roulette having fights occur with cats that go outside as FIV of course is not something you can cure and will eventually be fatal.

Marianne, we have tried to keep him in over the last couple of months but he is just too set in his ways.  He won't use a litter tray at all even if it's been 2 days! He just cries at the door.
Also, the back garden won't work as he just jumps over the fence as my dogs use that garden.
We have a huge field behind us but he would rather hang around the terrace, fighting!Pah!
I am worried about contagious diseases actually.  This is my main worry.  I do know that both my cat and this 'new' cat have had all their innoculations but I worry that if the black cat is a bit of a fighter, it might not just be our cat he's squabbles with.

There is no vaccine for FIV and for all you know the new cat could already be infected. Sorry to be doom and gloom, but  this is such a common story and creates so much stress for the cats. My cats have a large, fully enclosed run in the garden that they have access to 24/7 via a cat flap in the living room window. Many cats over many years have been very happy with this arrangement, even ex- feral rescues, and I know they are safe.

Thanks for all your replies.  I think I will need to think seriously about a catrun for him.  He has gave himself a curfew and is spending most of his time indoors thankfully.  He only nips out for the toilet.  If he keeps this up, I can live with it.

If you are able to this link is a cheap way to DIY cat proof your garden.

Oooo, thanks for that, Christine.  Lots of good ideas to save on costly mistakes!