Pillars of the Earth by Ken Follett (1989)
Despite its daunting size, this isn't a difficult novel. It reads like domestic fiction, a very different experience from The Game of Kings, for example. Although there's a lot of political maneuvering, Follett does a good job of explaining it all simply and clearly. I didn't need to look up any history to understand what was going on. It's quite seamless and fits neatly into the narrative of the story.
The real strength of this novel is in the characters. Prior Philip was orphaned as a child and brought to live in a monastery. A man of God, Philip nevertheless has his faults and must remind himself to keep his pride in check. Philip is smart - some called him sly - and very good at manipulating situations to work out in his favor, but also to benefit others as well, thus making everyone happy. Philip really wants to do what is right, and is especially fair-minded and just when compared to the corrupt clergy surrounding him.
There are a couple of villains in the story, but my favorite was William Hamleigh, the spurned groom who took revenge on his intended wife's family by usurping the earldom from her father. He's the worst kind of brute (his favorite game is "stoning the cat") and he spends most of his life raping, pillaging, and robbing at every opportunity. His cruelty stems from his fear of being laughed at behind his back, and his terrified of hell, ironic given the number and severity of crimes he commits despite his fear.
I don't know if this was intentional, but the main female characters led unconventional lives. Ellen, the wife of Tom, master builder of the cathedral, spent a lot of her life living in the forest and was thought to be a witch. Aliena, the intended bride of William, became a shrewd businesswoman who avoided romance. Even Tom's daughter Martha preferred to remain single, an unusual choice. But I suppose that's what makes the novel so compelling.
Since the backdrop is the construction of a cathedral, there's a lot of information about architecture woven into the story. At times I found it hard to envision exactly what was being described, but I got the important points which were primarily concerned with the development of different styles of architecture and solving various problems in bringing the builder's vision to life.
It's a rather fascinating time period, what with the violence and savagery and horrid treatment of women. Not to mention the civil war and the uncertainty of who would win the throne. People were so helpless in controlling the circumstances of their own lives, and it was crushing to see how their security was pulled out from under them over and over again. If you want to spend some time with a book, reading a long story arc spanning decades of the characters' lives, this would be a good choice.