History of the Siege of Lisbon - a novel about so many things, including writing a novel

Of course there are 2 sieges going on in Jose Saramago's The History of the Siege of Lisbon. On one level, the main character, the proof-reader turned author-(anti)historian, Raimundo Silva, is recounting the eponymous history, but it's not a historical re-telling, it's a retelling of history by his own rules, following the suggestion of his boss at the publishing house, he pursues the consequences of his insertion of the word "not" in a "real" history he'd been proof reading and he embarks on a telling of his own: the Portuguese troops under leadership of their kind prepare to lay siege to Lisbon and oust the Muslim Moorish populace the controls the city - but in this case, thanks to Raimundo Silva emendation, "not" with the aid of an army of crusaders - in other words, he has made his history into fiction; the 2nd siege, though, RS's attempt to win the heart or at least the attentions of his boss, the supervisor of proofreaders, Maria Sara (?) - he very very gradually gets closer to her, recognizes that in some slight way she may be interested in him as well, and then, over many tortuous pages, debates whether to call her at home - he's like any love-sick teenager, albeit more analytic and proper - but of course he seems to in his 40s or so and quite a social isolate. In any case, he gets up the nerve to call and, surprisingly, she reciprocates - she's very interested in him - so that siege is ongoing, every bit as complex as the historical narrative RS is developing with the Portuguese troops planning a simultaneous assault on the 5 gates of Lisbon. But we cannot forget - if RS is managing two assaults, the one in his writing and the other in his life, the real author, Saramago, is managing all of these assaults - the characters are all his characters, and, certainly, as an American reader, I have no idea how much he's invented as part of his history of the siege (of Lisbon) and how closely he hews to historic fact - or if we even know what historic fact is, or means. Saramago has one very insightful passage about the technical difficulties any novelist faces in describing the actions and reactions of two characters at the same time, separated in space (in this case, both RS and MS following their phone conversation) - so this novel, which is about so many things (history, romance, contemporary Lisbon, publishing, border between fact and fiction, border between known and unknown), is also about the art of writing a novel.