Territory is your pride's space to live in.
Territory is displayed in your den, next to your lion's name.
You start with territory of size 2. A little plus next to it shows that you can expand it.
Territory - holding lionesses, sub males, and cubs
You yourself aren't counted towards territory space.
Territory shows how many subjects you can have - territory of 7 means you can have 7 lionesses, 6 lionesses and 1 suboridinate male, 5 lionesses and 2 subordinate males, and so on.
You need one extra territory space for a breeding, to ensure your ladies that you can support future cubs. You also need at least one extra territory space to claim wild lionesses.
So with 7 territory and 6 lionesses, you can breed and get them pregnant. Cubs won't take territory space until they adults- but make sure that you have enough of space for them if you want to keep them and they're already teenagers! (over 1 year old)
You can always free territory space by chasing off lions.
Chasing off a lioness/sub. male frees 1 spot.
Chasing off lioness with little cubs under 1 age will also make the cubs run away, frees 1 spot.
Chasing off a cub won't cause any repercussions.
Territory size and expansion
You can buy more territory up to 20 size by clicking a plus in your den and spending Silver Beetles on it.
Above 20, up to 40, your only way to get more territory is to attack another lion. Attacking other lions
You can attack for territory as many times a day you like - but another lion can be attacked for it only ONCE a day.
You can't attack a lion who has only 2 territory.
From territory size 40 and forever on, the only way to get it expanded is to spend 2 GB per space. It's a luxury.
Territory maximum size is unlimited for a single lion to take care of, as long as you have the GB to get it.