Is the center important?

I know central control is imperative in the opening and crucial in the middlegame, but is it relevant in the endgame?

In the endgame, we rarely see d and e pawns promote, the same files are generally not occupied by the rooks and the bishops never linger on the long diagonals. Kings and knights being short range pieces tend to move towards the center in preparation for an endgame, but relocate to the hot spots when the endgame actually comences.

Am I wrong in concluding that control of the center is no longer relevant when a game reaches it's end?

Well, as the number of pieces on the board dwindles, it becomes less likely for either player to control the center. But, during the opening and middlegame, a king in the center of the board is dangerous. But many people thinkk that the endgame has arrived when one no longer must worry about king safety.

I think you have a point. As the game reaches an end and there are few pieces left then very often central control becomes irrelevant and passed pawns on the a and h files are the determining factors 

In the endgame, the goal is to promote pawns, (as opposed to attacking with the pieces you have, like in the first two phases) because, usually, that's the only way to win the game at that point, so the squares to control are utterly relevant to where the passed pawns are at. It all depends on the objective, I think.

I often find that by the end-game many of my remaining peices are disaffected.

I think you stated the point perfectly. Central control does not become unimportant in the endgame. Central control becomes irrelevant in the endgame. The important issues have shifted. It may still be important to control the center in the endgame (if this is where the action is taking place) but it would be for different reasons than the general dogma of opening theory.

Agree

Yes the center is absolutely important in the opening and mid-game as far as end it can be anywhere. Here is a game in which I won where the middle was my territory -

the centre is important in endgame situations where the centre is important! eureka! it is impossible to make a blanket rule for the whole of endgame theory. the chess position is a variable thing, so the ideas that are applied to find the chess truth in each position is equally variable. bingo

the parent idea of centre control is to have greater movement for your pieces, to extract all their power. The same parent idea applies to the endgame, you want to bring out the maximum potential of your pieces. A lot of the time in the endgame the play will be on the wings due to the previous elimination of centre pawns, and also due to the manner in which we try and reduce the power of the king, by trapping him on the side of the board where he can't have any influence. This is similar to the knights vs bishops arguement. The centre is no less important than the sides of the board, but the natural flow of a majority of games just leads to play on the wings.