epoch-making

"That seems to me like a very mild statement, but I suppose they considered it epoch-making," remarked Fowler.

On the 17th of September, 1894, an epoch-making battle of these iron-clads took place.

The period is the first half of that most fascinating, picturesque and epoch-making century, the eighteenth.

To both men the weeks just ended, including those which had elapsed since their return had been epoch-making.