The NYT has a fine, long obituary, that captures much of the complexity of the man. (The Guardian has a brief, perfunctory obit, the barest courtesy. Perhaps they didn't like him. I'm not even going to link to it).
Solzhenitsyn was one of the formative figures of my life. As a child and teenager I heard of him, obviously, but hadn't read any of his books. I eventually did so during my university years. The final push came when I read Terrence Des Pres, The Survivor. The Survivor is near or at the top of the shortlist of best books I've ever read about the Shoah; it's an attempt to understand how people survived the camps. As worthy of a book seeking the fundamental truth rather than the froth, Des Pres began his disquisition with a reading of the more important literary efforts about the camps, and Solzhenitsyn was cited heavily.
Once I'd read Des Pres I spent most of a summer reading Solzhenitsyn's books, one after another. He talked about cruelty and suffering, malice and hope, callousness and friendship. Without elaborating on the word, he described evil. His books inured me forever - had I ever been so inclined - of the ability to relativize, to excuse away, to engage in foolish comparisons between mundane wrong doing and strategic large scale destruction.
As the NYT obit tells:
In some countries, people were interrogated until suicide for telling the truth. In others, they get bad-mouthed in the literary circles. Long live the difference.
By this time, Mr. Solzhenitsyn had completed his own massive attempt at truthfulness, “The Gulag Archipelago.” In more than 300,000 words, he told the history of the Gulag prison camps, whose operations and rationale and even existence were subjects long considered taboo.
Publishers in Paris and New York had secretly received the manuscript on microfilm. But wanting the book to appear first in the Soviet Union, Mr. Solzhenitsyn asked them to put off publishing it. Then, in September 1973, he changed his mind. He had learned that the Soviet spy agency, the KGB, had unearthed a buried copy of the book after interrogating his typist, Elizaveta Voronyanskaya, and that she had hung herself soon afterward.