Margaret impressed not only Malcolm but many other members of the Scottish Court both for her knowledge of continental customs gained in the court of Hungary, and also for her piety. She became highly influential, both indirectly by her influence on Malcolm as well as through direct activities on her part. Prominent among these activities was religious reform. Margaret instigated reforms within the Scottish church, as well as development of closer ties to the larger Roman Church in order to avoid a schism between the Celtic Church and Rome. Further, Margaret was a patroness both of the célidé, Scottish Christian hermits, and also the Benedictine Order. Although Benedictine monks were prominent throughout western continental Europe, there were previously no Benedictine monasteries known to exist in Scotland. Margaret therefore invited English Benedictine monks to establish monasteries in her kingdom.
On the more secular side, Margaret introduced continental fashions, manners, and ceremony to the Scottish court. The popularization of continental fashions had the side-effect of introducing foreign merchants to Scotland, increasing economic ties and communication between Scotland and the continent. Margaret was also a patroness of the arts and education. Further, Malcolm sought Maragret's advice on matters of state, and together with other English exiles Margaret was influential in introducing English-style feudalism and parliament to Scotland.
Margaret was also active in works of charity. Margaret frequently visited and cared for the sick, and on a larger scale had hostels constructed for the poor. She was also in the habit, particularly during Advent and Lent, of holding feasts for as many as 300 commoners in the royal castle.
King Malcolm, meanwhile, was engaged in a contest with William the Conqueror over Northumbria and Cambria. After an unsuccessful 1070 invasion by Malcom into Northumbria followed by an unsuccessful 1072 invasion by William into Scotland, Malcom paid William homage, resulting in temporary peace. William further made assurance of this peace by demanding Malcolm's eldest son Donald (by Malcolm's previous wife Ingibjorg) as a hostage. Time passed, William the Conqueror died, and The Conqueror's son William Rufus took the throne of England. Hostilities again arose between Scotland and England, and in the ensuing unpleasantness Malcolm was killed along with Edward, the eldest son of Malcom and Margaret.
Margaret had already been ill when Malcolm and Edward went off to battle. Her surviving children tried to hide the fact of their deaths, for fear of worsening her condition. But Margaret learnt the truth, and whether due to her illness or a broken heart, Margaret died four days after her husband and son, on November 16, 1093.
The death of both King and Queen led, unfortunately, to yet another unpleasant disagreement, this time over who should take their places on the throne. The most likely candidate was Malcom's eldest son Donald, the one who had been taken hostage by William the Conqueror. This was also the favorite candidate of William Rufus, for during his stay in England Donald had developed a favorable view of the Normans. However, Donald's claim to the throne was contested by Malcom's brother, Donald Bán, together with Malcom and Margaret's son Edmund. Donald Bán was opposed to having a Norman sympathizer on the throne of Scotland, and claimed the throne for himself. Both Donald MacMalcom and Donald Bán held the throne briefly, and lost it violently, before Edgar, son of Malcom and Margaret, came to the throne. He was succeeded by his brothers, Alexander and David. Alexander smoothed over relations with England by marrying the daughter of King Henry I and arranging for Henry to marry Alexander's sister Matilda. Edgar and David carried on their mother's reputation for sanctity, both in their service to the poor and their patronage of religious orders, and David was later canonized. Quite a celebrated family when you consider that Margaret's uncle is also known as Saint Edward the Confessor.
Margaret herself was declared a saint in 1250, particularly for her work for religious reform and her charitable works. She herself was considered to be an exemplar of the just ruler, and also influenced her husband and children to be just and holy rulers. She was further declared Patroness of Scotland in 1673.
Feast Day: June 10 (celebrated November 16 in Scotland)