Rose Tyler is a fictional female Human in the Doctor Who series. The character was portrayed on screen by Billie Piper. Her allegiance / loyalty is to The Nineth Doctor. Rose Tyler was the first of The Doctor's assistants when the series returned after a long break. She gets involved with The Doctor when he is on Earth trying to discover the source of an Autons attack. The adventure leads to the Doctor blowing up a department store in London and travelling under the city to find the control source of the Autons.
In the series, Rose has one boyfriend and that is Mickey Smith. When Mickey decides to stay in the other universe because he has family there, Rose prefers to stay in this dimension. When the Cybermen from the alternate universe come back through to ours, Rose is reunited by Mickey. The relationship doesn't seem to last as eventually Mickey marries Martha Jones but its not clear how those two met.
In the alternate universe where the new Cybermen come from, there is no Rose Tyler. The only Rose is a dog that is owned by Jackie and Pete Tyler. Rose wants to stay in this universe because she wants to carry on travelling with the Doctor.
Rose's Mum wants to live in the other alternate universe so that she can be with Pete because in this universe Pete is dead. At the last moment, before the multiverse portal is closed, Pete comes through the portal to take Rose into the other universe just as the doorway closes.
Rose makes trips through the multiverse portal on a number of occasions such as in Partners in Crime where she makes a guest appearance.
Rose lives with her Mum, Jackie on a council estate. Rose's father is killed in a car incident when Rose was young and didn't get to know him that well when he was alive. Against the Doctor's better judgement, the Doctor takes Rose back to just before Rose's dad is killed so she can see him one last time. However, Rose couldn't resists interferring in the timeline and rescues her dad thus preventing his death (Fathers Day) which causes time and space to collapse and creatures that feed on disharmony to appear and cause damage. The only way for time and space to return to normality was for Rose's dad to kill himself which he does.
Rose gets to meet her father once more when an accident onboard the Tardis causes a trip through time and space through the multiverse to another dimension. In the alternate reality, her father is alive and well and a successful businessman. In the alternate reality, Rose as we know is not born but is a dog. Rose's mother in the alternate reality is killed by being turned into a Cyberman.
Rose's mum from this reality travels through the Multiverse and is reunited with Rose's father where they fall in love although they were not out of love. At the end of the Battle of Canary Wharf when Cybermen from the alternate reality invade our reality to fight off against the Daleks, Rose is pulled through into the alternate reality where she is with her mum and father. The dimension portal closes and she is unable to return to our reality and so the Doctor goes off to get a new companion.
Its not the last time we see Rose as she makes a return to our reality to help the Doctor having found a way through the dimension portal. She appears in the Partners in Crime to help the Doctor and Donna Noble to deal with the Adipose.
Rose forces the Doctor to regenerate when she realises that she is Bad Wolf, a word that throughout her journey she kept seeing. Rose looked into the heart of the Tardis and gained so much power that the Doctor had to remove the power and regenerate.
Rose Tyler is played by Billie Piper, a singer turned actress. Before she won the hearts of the Whovians, a lot of people thought it was a bad idea but she managed to win over people and is one of the best loved Doctor (ref: IMDB Poll). At the time of writing, she was number 1. She returned to the series as vision of the Tardis where she talks to the War Doctor, the forgotten incarnation of the Doctor. I doubt we've seen the last of her given her reverence
Billie Piper who played Rose Tyler for the first two years when the series returned to the television with Christopher Eccleston and David Tennant came back for the 50th anniversary. Billie didn't play Rose Tyler, her character was the Moment. The Moment was a weapon device that when used earned the John Hurt incarnation of the Doctor, the title The War Doctor.
The War Doctor is the incarnation of the Doctor that the other incarnations like to forget about hence why the character was never mentioned. He came after the Eighth Doctor played by Paul McGann which resulted in all the new Doctors shifting up one.
The Moment was a war device, something that could destroy whole planets, aliens and galaxies in a single moment hence its name. It could project itself as a person to the person who had the device. The Moment projected itself as Rose Tyler which the machine announced it didn't know if the companion was from the past or the future but one we know.