IN Galloway, on May 11, 1685, a woman of 63 and an 18-year-old girl were escorted to a point near the mouth of the River Bladnoch, below the town of Wigtown, where they were fastened to stakes in the water and left to drown. This was the newly decreed punishment for female traitors. Margaret Lachlan or McLachlan and young Margaret Wilson had joined the ranks of those who gave their lives in the cause of the National Covenant.

Today a simple cairn, topped by a rough granite pillar representing a wooden stake, marks the spot. The inscription is as follows: This Marks The Traditional Site of the Martyrdom.

High on the Wigtown skyline is another reminder, the tall Windyhill Monument to the Covenanters where their names, along with those of William Johnstone, John Milroy, and Gilbert Walker, were inscribed. The carefully-preserved gravestones of all five may still be seen in Wigtown churchyard. A more elaborate but less appropriate monument to the two women stands in the Valley Cemetery in Stirling, beside the Church of the Holy Rude. A marble plaque says: ''Margaret Virgin Martyr of the Ocean Wave with her like-minded sister, Agnes.''

Encased in glass are statues of two young girls, with their guardian angel hovering over them. Sadly, vandals have clipped the angel's wings and the unfortunate girls have been beheaded. We find no mention here of the older woman, Margaret McLachlan, and so far as is known ''like-minded'' Agnes died peacefully in her bed.

Not everyone accepts the account of the Wigtown Martyrdom, and young Margaret Wilson has been dismissed scathingly as the ''prima donna of that water opera''.

Twenty-two years after the signing of the National Covenant, Charles II returned from exile and by 1662 Episcopathy was reintroduced as the compulsory form of Scottish church government. As a result over 300 Presbyterian ministers were expelled for refusal to compromise their beliefs, and in Galloway, where the Covenanting flame burned brightly, only three remained in their charges. Such was the religious climate into which young Margaret Wilson was born at Glenvernoch, a farm in the parish of Penninghame, near Newton Stewart in Wigtownshire.

Despite the ''Bishops' Dragnet'', making attendance at Episcopalian services obligatory, many attended Conventicles, held on remote moors or hillsides, where some of the ejected ministers continued to preach. Young Margaret's parents, however, were obedient Episcopalians, although she and her brother, Thomas, were beginning to backslide. Facing fines for their absence from church, their father may have questioned the implications, their older brothers having joined the ranks of the Covenanters hiding out nearby.

It began innocently, with Margaret and Thomas carrying food to their brothers. If their sister, Agnes, followed, they didn't worry unduly. Their parents, torn in the allegiances, allowed them to go, provided they kept clear of illegal gatherings. Then, one day, hearing Jack Renwick, the new leader of the Cameronians - a more extreme breed of Covenanters - was preaching locally they succumbed to temptation. They had to see this man.

In the emotionally-charged atmosphere of the conventicle field the silence was disturbed only by the cries of the curlews - betrayers of many conventicles - circling overhead. The slight, golden-haired lad in his early twenties who stepped forward looked an unlikely leader of a rebel band. Well educated, Renwick could be warm and gentle, yet totally uncompromising in the cause of the Covenant. Probably Margaret's commitment was made on that day.

The other Margaret had known the Covenanters' struggles from the beginning. She was old enough to have signed the National. Covenant and committed enough to remain true to it.

Now less able to attend conventicles, this elderly widow of a local joiner regularly provided sanctuary for the fugitives in her home above Kirkinner, but although under suspicion, she was never caught. She gave God all the glory but also had a good lookout system.

Young Margaret began to slip away to the conventicles at every opportunity. These were usually small gatherings held in barns or cottages, for large conventicles were now rare events, as most of the hill-preachers were dead or in prison. Sixteen-year-old Thomas sometimes accompanied Margaret and if Agnes insisted in going too, who would question a 12-year-old? As a hard-working bunnet laird Gilbert Wilson had other things on his mind, and his wife a brood of bairns to distract her. Their older sons now having fled the country, they had no reason to suppose Margaret and Thomas would go near a conventicle. By the time they found out, the damage was done.

By 1684 refusal to take a Test of Allegiance to the king - which included an Oath of Abjuration renouncing the Covenant - became a capital offence. So, too, was attendance at conventicles and harbouring Covenanters. These drastic measures were the government's answer to a defiant and challenging Cameronian manifesto, prompting Graham of Claverhouse into swift retaliatory action. Bluidy Clavers was so-called with good reason - this man who was later lionised as Bonnie Dundee.

Because of their youth the youngsters had so far avoided punishment, but now all three were in real danger. They had also endangered the lives of their parents. Thomas decided to take his chances with the hillmen and the girls fled for cover to a remote unoccupied cottage. Held responsible, their father was forced to billet large numbers of soldiers, who plundered and destroyed, leaving him destitute.

With help from their parents, Margaret and Agnes survived for several months - but the net was tightening. The Penninghame Kirk Session records take over the story: ''. . . the said Thomas keeping to the mountains, his two sisters, Margaret and Agnes, went secretly to Wigtown to see some friends, these two were there discovered, taken prisoners, and instantly thrust into the thieves' hole as the greatest malefactors.''

The two girls clung together in the hole in which they found themselves. At one point they were marched out to take the Abjuration Oath and thrown back when they refused. Their father was allowed to visit, his heart constricting at the sight. Wigtown Provost Coltrane told him the girls had been incarcerated out of concern for the town's safety. Gilbert Wilson vowed to get them out. The following Sunday, Margaret McLachlan was arrested and thrust into the Thieves' Hole alongside the Wilson girls and a servant, Margaret Maxwell.

They were brought before the Government Commissioners for Wigtownshire, who included Grierson of Lagg, and indicted with rebellion at the battles of Bothwell Bridge and Aird's Moss. There was also the vexed matter of the Abjuration Oath. Regarding the conventicles, the women admitted guilt.

Margaret Maxwell was found partially guilty and sentenced to be flogged then chained to the pillory for an hour, on three successive days. The others were pronounced guilty of all charges. The Penninghame Session records tell us, ''. . . the judged sentenced them to be tied to palisades fixed in the sand, within the floodmark of the sea, and there to stand till the flood o'erflowed them''. At the news, Thomas Wilson was beside himself and Gilbert galloped off to Edinburgh to plead their cause with the Privy Council. He also carried a petition, written on Margaret McLachlan's behalf, falsely claiming she had recanted. Could Gilbert have lied, too, in this connection in a desperate attempt to save his daughters? On a bond of 100 Pounds Scots, Agnes was granted freedom, and reprieves, dated April 30, 1685, were written out on behalf of the others.

It has been claimed the condemned women at this point did renounce the Covenant and their lives were spared. Yet Kirkinner and Penninghame Kirk Session records give a detailed account of the events. That these records were written more than 20 years later may be explained by the Church of Scotland's request for information about the sufferings of the Covenanting period. The Penninghame record includes these words: ''. . . he (Thomas Wilson) lives to certifie the truth of these things, with many others who knew them too weel''. This was Margaret's brother. Similarly, Margaret McLachlan's daughter testified to her mother's drowning.

The reprieves never arrived. The grey desolate morning of May 11 matched the mood of those who watched as dragoons escorted the two women to a point near the mouth of the Bladnoch.

To ensure Margaret Wilson would die first, she was placed nearer the point where the Bladnoch and Solway converge, a considered strategy to shock young Margaret into submission. The older woman showed great courage throughout and when given a final opportunity to take the Oath she refused. Kirkinner Kirk Session records tell us she was ''held down within the water by one of the town-officers by his halbert at her throat till she died''.

Margaret Wilson witnessed this without wavering, and when the tide-water surged up the channel, we are told she began to sing from the 25th Psalm.

As the waters threatened to engulf her, Grierson of Lagg, whether moved by compassion or merely playing a perverted game of cat and mouse, ordered her release. Supported by soldiers on the riverbank, the semi-conscious girl was then asked by Lagg to swear allegiance to the king and renounce Renwick and his cause. ''Just say God Save the King, Margaret,'' cried the crowd.

''God save him if he will,'' she answered. It was not enough.

Her distraught mother implored her to take the Oath, and this was echoed by the onlookers.

''Take the Oath, Margaret.'' Still she refused.''

I will not,'' she replied, fighting for breath.''I am one of Christ's children. Let me go.''

And so she was returned to the water.

On February 17, 1688, James Renwick died on the last Covenanting scaffold, aged 26. Presbyterianism was reinstated two years later.

n Footnote: A descendant of Margaret Wilson's family was Thomas Woodrow Wilson, 28th President of the United States whose eldest daughter was named after Margaret. This information from Donna Brewster's book, Second Daughter, is gratefully acknowledged.