The feast day of St. Machar occurs on the 12th of November each year.
Saint Machar is the patron saint of Aberdeen, which can't be a bad thing as there surely aren't many saints in the Granite City. However, the trouble with Machar is that despite 'giving' his name to the cathedral church in Aberdeen, he's kind of invisible. Reputedly a 6th Century missionary, who was sent by St. Columba to preach on Deeside, he also goes by the names of Mochumma, Mochrieha or Mochreiha. Having a selection of names would appear to make him more visible to history, if only he could be pinned down. And that's the major problem, nowhere in the ancient biographies of St. Columba does Machar appear.
If you take the stories of Columba dispatching Machar to Deeside as gospel, surely
the latter saint would warrant a mention in the 'Life of Columba' written reasonably contemporaneously by St. Adomnán, the ninth abbot of Iona who knew monks who had known Columba personally. They also knew his followers. The most telling piece of lack of evidence for the existence of any Machar is the absence of his name from the list of the twelve 'disciples' who left Ireland with Colum Cille for their exile in Iona.
Basically, St. Machar is either a legend or at best, a case of mistaken identity – some say he's one and the same as St. Mungo. The legends have it that in A.D. 581, St. Machar received word from 'on high' that he should establish a church where a river bends into the shape of a bishop's crosier. Alternative stories suggest that it was Columba who gave Machar instructions to search for a place where a river formed the shape of a crosier and found a church. That alternative legend involves Machar being sent away, because his contemporaries were envious of his 'great powers'. Allegedly a missionary on Mull, Machar is said to have cured lepers and turned a wild boar into stone. So for the sake of peace amongst his flock, Columba sent Machar to convert the Picts. Mind you, he also sent Drostan for the same task.
Apart from the cathedral, which doesn't count, there three (only three) pieces of 'evidence' for the existence of a Machar in Aberdeenshire. A wee bit west of Aboyne Castle, there lies what's left of what was known as St. Machar’s Chair (Cathair Mochrieha). Not far away is St. Machar's Well and what's called St. Machar's Cross, cut into a nearby granite rock. In the days of Columba and his contemporaries, such as St. Mungo (Kentigern), Aboyne was the location of a Pictish hillside settlement and a notable place where folks could reasonably cross the River Dee. Maybe Machar, if he truly existed, never got as far as Aberdeen?
Nobody can say when Machar became a saint; the dates are not available, just as they are not for Columba, Mungo or Ninian for that matter. That means the personage who got the accolade of St. Machar could have been someone known locally as Machar, but with no connection to Columba's band of followers. Before the end of the 11th Century, it was common practice for local bishops or primates to confer beatification and/or canonization. It was also the case that those honours were always decreed only for the local territory over which the person conferring the accolade held jurisdiction. The practice of conferring universal sainthood is something the then Bishop of Rome introduced around the turn of the 12th Century, by which time St. Machar's legend was probably fairly well established.
St. Machar's 'history' stems from a late 14th Century verse account and, primarily, the Aberdeen Breviary, an early 16th Century Scottish Catholic liturgical book. As it was compiled long after the traditional date of Machar's life, it is probably wrong to take the Breviary, which contains brief accounts of various Scottish saints, at face value. The Breviary was edited by William Elphinstone and printed in Edinburgh, in 1507, by Walter Chepman and Androw Myllar.
The idea of a Machar being sent by Columba to bring Christianity to the Picts is also, to some extent, a bit dubious. It's claimed that Columba visited the northern Picts of the High King, Brude (Bridei mac Maelchon), in an attempt to bring them the Word of God, with that being the first they'd heard of the Christian deity. However, a quick look at the 5th Century St. Ninian will tell you that, at the very least, the southern Picts had been christianised around a century earlier than Machar and Columba. In fact, it's generally accepted that the Christian faith was brought to Ireland from Scotland and not the other way round, with a pupil of Ninian being one of the prime movers in that regard.
How come, if the southern Picts had been Christian, their northern cousins were oblivious to the situation; ask yourself that. The question is a good one if you accept that another of Ninian's pupils, St. Ternan, had established a church at Banchory (Banchor or Bangor) on the Dee, amongst the Picts, at the same time as St. Carnoc was striving to bring the Word to the heathens in Donegal, long before Columba's (and Machar's) birth.
Another piece of the puzzle regarding St. Machar is that the Book of Deer, a 10th Century illuminated manuscript from the earlier, 6th Century Pictish monastery at Old Deer in north-east Aberdeenshire, makes no mention of Machar. Quite strange indeed, considering the monastery is associated with one of Columba's mates, Drostan, ostensibly a good mate of Machar – if he existed as such. The Book of Deer, in the possession of the Monastery of Deer prior to 1000, is the only pre-Norman manuscript from that area and provides a unique insight into the early church, culture and society of the period.
St Machar's Cathedral in Aberdeen, the history of which does indeed go back to around 580 A.D., is named in Machar's honour, but don't forget that these days it's a Presbyterian church and a cathedral in name only – the Cathedral Church of St Machar. In days gone by, however, it was known as the Cathedral church of St. Mary and St. Machar, with the female saint's name being removed at some stage during the Reformation. What did poor Mary do wrong, you might wonder.