Extract from a blog post by Amanda McCrina:

I feel like I should rename this as ‘Books that will make you cry if you, in fact, cry for books.’ I don’t, typically. The following books particularly moved me—if I did cry for books these would be the ones that did it—but I think I only truly cried at the first. (Some spoilers follow, naturally.)

1) The Lantern Bearers, Rosemary Sutcliff.
Unsurprising to most of you who know me and my reading preferences. This is my favorite of her books, it’s very nearly my all-time-favourite book, and yes I have cried while reading it. Through most of the ending chapters, but especially at this part:

Aquila was staring into the fire, his arm across his knees. What was there to say to Flavia, after their last meeting, and the years between? And then he knew. He put up his hand and freed the shoulder-buckle of his leather tunic, and pulled it back; he dragged up the loose woollen sleeve beneath, to bare his shoulder, and leaned toward Mull in the firelight. ‘Look.’

Mull strained up higher on his sound arm, and looked. ‘It is a dolphin,’ he said.

‘A friend did it for me when I was a boy.’ He let his sleeve fall and began to refasten the buckle. ‘Ask her if she remembers the terrace steps under the damson tree at home. Ask her if she remember the talk that we had there once, about Odysseus coming home. Say to her–as though it were I who spoke through you, “Look. I’ve a dolphin on my shoulder. I’m your long-lost brother.”’

2) The Shining Company, Rosemary Sutcliff.
Not even among my top five of her books, probably, but undeniably a tear-jerker.

Source:  Top 10 Tuesday: Books to make you cry » Amanda McCrina — Historical fiction and fantasy; incl. The Lantern Bearers, Oxford University Press, pg. 292