Benedict Cumberbatch plays the tortured Christopher Tietjens, the last "Tory" an English country gentleman and statistician in an age where the squires and landowners are being politically overthrown and there is a new land of suffragettes, modern philosophy and battles (both literal and figurative) on the horizon. Tietjens is plagued by honour. He cannot fathom doing something that would break his moral code of conduct. Trapped in a loveless marriage to the absolutely fascinating Sylvia (seriously: Rebecca Hall is beautiful and beguiling in this role, she's as much a chameleon as Benedict ), Tietjens cannot reconcile happiness which doesn't fall into the carefully constructed line of social norms instilled in him by his great landowning Yorkshire father.
Sylvia is Catholic and doesn't believe in divorce, Tietjens moral code forbids divorce. So, even though it is questioned as to whether his son ( whom he loves to distraction ) is his own and no matter the nature of his wife's infidelity, Christopher is long-suffering. Several characters paint the canvas of both the Tietjens' town and country worlds: including a minister's wife and her mad husband, a Scottish critic who acts as friend and confidante to Christopher, and the indomitable suffragette Valentine Wannop, a young athlete and radical whom Christopher meets and subsequently muses on for most of the series.
So much of the prelude to the War is an intricate waltz between Sylvia and Tietjens. Sylvia is mad for her husband and desperately wants his attention. Christopher isn't sure what to do with his wayward wife; but refuses to take a mistress no matter how it would equalize their playing field and perhaps, as Sylvia muses, bring them closer together.
What begins is the downward spiral of a tragic hero. The rumours which begin spinning about
Christopher's own infidelity are made even worse by the forbearance he shows against their telling. In one case, he is said to have been involved in a sexual affair on a train; whereas, in actuality, he was escorting a woman and offering help to his friend and his friend's new mistress. It is heartbreaking to see someone who falls on his sword again and again to do what is right, be cast off again and again by a society who cannot believe in his inherent honour. Indeed, it seems more as if they cannot tolerate his goodness because they know they cannot live up to it. He must be taken down a peg.
Even Sylvia knows that her husband would never dishonour her; though his rapport with Valentine irks her jealousy until she begins spreading a few tall tales of her own.
At several points I wanted to shake everyone: pay attention, Christopher! Your wife is just trying to get you to notice her! Sylvia, come on! He doesn't expect you to be up to his level, he is taking you as you are and there is NO NEED to be a conniving fox. Christopher's strict and stalwart core make him a martyr for his own cause. He needs happiness! Love! A chance!
If this waltz had continued, it might have played into the soap-like tendencies of Fellowes' Downton; instead it introduces the War and severs entirely the world that Tietjens knew.
Tietjens comes into his own not when he is acting in high command, training Canadian troops (he sticks up for the Canadians as more than conscripts! Score! ) ; but when he is lowered into the trenches, forced to confront the enemy, without his title or his traditions to hide behind. One lovely moment sees a young soldier bringing him coffee and a sandwich on a china tea service while the muck and debris of the trench falls around him. After finishing his dainty repast---a complete contrast to his present situation--- Tietjens smashes the china tea cup against the muddy wall. He is someone else now, he has come into his own when stripped of high title and ranking and equalized with the war.
All of the uncertainty, all of the muddled confusion strips away and Tietjens finds a new purpose and family. When the war is over and he returns home to find that his wife has heartlessly chopped down the great ancient cedar at Groby Estate, a symbol of era upon era of Tietjen prosperity and reign, he can finally throw a chopped log of its once-grand branches into a fire, he can dance alongside his new officer comrades, he can take his suffragette into his arms.
The world has changed. The last Tory has expired: not from death; but from new life. A man went through the war (on the home front and in the trenches) and emerged the best of a waking civilization. He just had to leave a lot behind.