In season one we are introduced to the local community through the eyes of young nurse Jenny Lee as she lives and works as a midwife alongside the Nuns of the Order of St. Raymond of Nonnatus in the deprived Poplar district of London's desperately poor East End in the 1950s.

The second season sees young nurse Jenny Lee continue her work as a midwife in the local community alongside the Nuns of the Order of St. Raymond of Nonnatus.

This season, Chummy, PC Noakes and baby Freddy are back in the East End and Jenny faces huge challenges both personally and professionally.

Season four finds the community preparing to enter a new decade - the 1960s. Nurse Trixie receives a proposal from handsome young curate Tom Hereward. Nurse Cynthia starts to think seriously about joining the order as a nun, something that shocks both Trixie and Patsy. And an unexpected set of events sees Chummy take on the challenge of running a mother and baby home for unmarried girls.

In season five, Sister Monica Joan goes missing at Christmas time leaving the nuns and nurses distraught. Shelagh rushes to put together a children’s choir in time for a BBC broadcast from the church. Elsewhere Trixie, having battled through her issues with alcohol, finds a new purpose in her keep fit classes. And could friendship blossom into something more for vicar Tom Hereward and Barbara?

It is now 1962, and the Nonnatus House team are as committed to caring for the people of Poplar as always. However, the social revolution in the outside world is mirrored by change and challenge much closer to home. As they strive to help mothers and families cope with the demands of childbearing, disability, disease and social prejudice, our beloved medics must make choices - and fight battles - of their own. Series six will see them laugh together, cry together, and pull together, supporting each other as never before.

In series seven, the nuns and nurses are tested as they have never been before, both personally and professionally. All around them they see the old East End vanishing, as slum clearances make way for bold new tower blocks to accommodate expanding communities. Their work brings them into contact with a wide range of challenges, from leprosy and stroke, to Huntington's chorea, cataracts and unmarried mothers. Trixie's romance with Christopher continues to develop, while Tom and Barbara enjoy life as a married couple. Nurse Crane finds her authority questioned from an unexpected quarter and Sister Monica Joan is forced to accept her failing faculties. Meanwhile, life for the Turners is turned upside down when Shelagh decides to employ an au pair.

It is now 1964 and it's evident how the times are changing: from the beacon of the contraceptive pill and the shadow of the 1967 Abortion Act, to the introduction of a new cancer-screening program. The nuns and nurses continue to face a variety of challenging issues including interracial adoption, cleft palate, sickle cell and cot death. And for one of the team, romance could be on the horizon.

The medics and midwives of Nonnatus House are entering a bold and innovative era. They face unexpected challenges as the population shifts, rules change, and old diseases come back to haunt them. Meanwhile, their own experiences are fueled by love, loss, and doubt. And the very future of Nonnatus House comes under threat.

It’s 1966, and it’s a testing time for the midwives. But there’s excitement, too, as the women’s rights movement intensifies. With Trixie’s help, Sister Julienne is determined to steer Nonnatus House out of its financial quandary.

Following an eventful Christmas, the midwives return to their rounds in East London in Easter 1967. Celebrations are underway for a colourful Easter Bonnet parade outside Nonnatus House. Sister Monica Joan and Reggie are excited about the Eurovision song contest and Nancy, having just passed her midwifery examinations, is about to don her red cardigan for the first time.

It's 1968 and Enoch Powell's infamous "Rivers of Blood" speech creates serious tension in Poplar, especially when a group of dockers march in support of Powell. The midwives welcome a new nun, Sister Veronica, who's an instant hit with everyone - except Nurse Crane. Meanwhile, Trixie's relationship with Matthew goes from strength to strength, while Nurse Crane helps Nancy with her financial woes. Sister Julienne enjoys helping out on the district rounds, Shelagh and Dr Turner split their time between the busy maternity home and their lively young family, while Reggie continues to bring joy into Violet and Fred's lives.

It is now 1969 and more babies are being born in hospital than ever before. Pressure on maternity beds remains extremely high across the country but Poplar is coping better than most due to the work of Nonnatus House and the popularity of home births under the auspices of the Sisters.