Tom Branson was a character on the series, Downton Abbey. He was played for most of the series run by actor Allen Leech.
From Chauffeur to Gentry
Tom Branson was first introduced to Downton Abbey as the Crawley family's chauffeur. He was also a very strident socialist, who was not very accepting of the gentry and their stranglehold on things.
Born in Ireland, he became Chauffeur after the previous one, Taylor, would move on and open up a tea shop. While there, he would fall in love with Lady Sybil Crawley, whom he discovered was just as political as he was.
After he tried to go off to war (he was refused to be drafted because of a heart murmur), he would finally get Sybil to accept his proposal of marriage. They would elope to Gretna Green, with only her sisters to witness.
Tom and Sybbie
Soon, he would become the father of a daughter, Sybil Branson II. Soon after her birth, her mother would die of Eclampsia. This would thrust Tom into becoming both mother and father to his newborn baby daughter (a rarity in those days).
He threw himself into it with a vengeance, as he was the only parent Sybbie had. It was clear to everyone that he adored his daughter and to him, the sun rose and set on her. He cherished the times that he and Sybbie could walk the grounds of the abbey and spend time together as father and daughter.
In a way, which would sometimes aggravate Sybbie's nanny, he would sometimes try to sneak into the nursery and kiss his little girl, reminding him of when his mother would do the same to him and Kieran. He would work hard to teach Sybbie about her Irish heritage (she was half-British, from Sybil's side of the family and half Irish from Tom's side), when she grew up.
Tom's life after Sybil
Tom would be the target of a crush by conniving Edna Braithwaite, but her scheme would not come to anything, as she would be sacked by Mrs. Hughes, one of Tom's friends from his days as a chauffeur, after trying to trap him into marriage.
He would later fall for a teacher named Sarah Bunting, who was just as much of a socialist as he used to be. His political beliefs used to annoy his father in-law, Robert Crawley, but as time wore on, he would become very fond of him.
As a christening gift from his late Sybil, Tom would be named the new Estate agent. At the request of Sybil, Sybbie would be christened as a Catholic, like her father. Her godparents would be her aunt Mary, and her uncle Kieran.
Interestingly, Sybil's granny, Violet Crawley, would grow to love him as she felt him to be the most practical of everyone in the Abbey. She also saw him as the calm and sensible voice of reason of the family.
After Sarah Bunting left Downton, he would later catch the eye of (and vice versa) of a woman named Laura Edmunds. They would meet at the racing at Brooklands. Laura was the editor of his sister in-law, Lady Edith Pelham's magazine. To Tom, he had come a long way from his beginnings as a outspoken and very socialistic chauffeur.
At first, he would be dealing with many crises of where he was. It took his friend, Mrs. Hughes, to make him see that he was the bridge between the upstairs family and the servants.
He would leave Downton for a time when he and Sybbie would move to Boston to live with one of his cousins, but they would come back to Downton to live there for good, when they realized that they were home, and Downtown would ALWAYS be their home.
They would come to the wedding of Carson and Mrs. Hughes, and surprised everyone in the village with their appearance, and a happy and touching reunion between the family ensued.