He was born about the year 1476, was educated in the Popish religion, and made priest of Lunan in the shire of Angus, where he remained until he was accused by the bishop of St. Andrews of having left off saying mass, which he had done long before this time, being condemned by the cardinal on that account, in the year 1538; but he escaped the flames for this time, by flying into Germany, where he married a wife, and was more perfectly instructed in the true religion; after which he returned home, but kept himself as retired as possible; during which time he went about reproving vice and instructing people in the grounds of religion, which coming at length to the ears of the ecclesiastics, in 1558, he was, by order of the bishops, apprehended in Dysart in the shire of Fife, by two priests, and imprisoned in the castle of St. Andrews, where the Papists, both by threatening and flattery, laboured with him to recant, offering him a place in the abbey of Dunfermline all the days of his life, if he would deny what he had already taught. But continuing constant in his opinions, he was brought to a trial before the bishops of St. Andrews, Murray, Brechin, Caithness, &c. who were assembled in the cathedral of St. Andrews. When he came to make his defence, he was so old, feeble and lame, that it was feared none would hear him; but as soon as he began to speak, he surprized them all, his voice made the church to ring, and his quickness and courage amazed his very enemies.

At first he kneeled and prayed for some time, after which one Sir Andrew Oliphant a priest, called to him to arise, and answer to the articles of charge, saying, "You keep my lord of St. Andrews too long here;" nevertheless he continued some time in prayer, and when he arose, said, "I ought to obey God more than man. I serve a mightier Lord than your lord is, and whereas you call me Sir Walter, they call me Walter; I have been too long one of the pope's knights: Now say what you have to say."

Oliphant began his Interrogations as follows:

Olip. Thou sayest there are not seven sacraments?

Mill. Give me the Lord's Supper and Baptism, and take you all the rest.

Oliph. What think you of a priest's marriage?

Mill. I think it a blessed bond ordained by God, and approved of by Christ, and free to all sorts of men; but ye abhor it, and in the meanwhile take other men's wives and daughters: Ye vow chastity, and keep it not.

Oliph. How sayest thou that the mass is idolatry?

Mill. A lord or king calleth many to dinner, they come and sit down, but the lord himself turneth his back, and eateth up all; and so do you.

Olip. Thou deniest the sacrament of the altar to be the real body of Christ in flesh and blood?

Mill. The scriptures are to be understood spiritually and not carnally, and so your mass is wrong, for Christ was once offered on the cross for sin, and will never be offered again, for then he put an end to all sacrifice.

Oliph. Thou deniest the office of a bishop?

Mill. I affirm that those you call bishops do no bishop's work, but live after sensual pleasure, taking no care of Christ's flock, nor regarding his word.

Oliph. Thou speakest against pilgrimage, and sayest, It is a pilgrimage to whoredom?

Mill. I say pilgrimage is not commanded in scripture, and that there is no greater whoredom in any place, except in brothel-houses.

Oliph. You preach privately in houses, and sometimes in the field?

Mill. Yea, and on the sea also when sailing in a ship.

Then said Oliphant, "If you will not recant, I will pronounce sentence against you."

To this he replied, "I know I must die once, and therefore as Christ said to Judas, What thou dost, do quickly: you shall know that I will not recant the truth, for I am corn and not chaff: I will neither be blown away by the wind, nor burst with the flail, but will abide both." Then Oliphant, as the mouth of the court, was ordered to pronounce sentence against him, ordaining him to be delivered to the temporal judge, and burnt as an heretic. But they could not procure one as a temporal judge to condemn him. One Learmond, then provost of the town, and bailie of the bishop's regality, refused it, and went out of town; the people of the place were so moved at his constancy, and offended at the wrong done to him, that they refused to supply ropes to bind him, and other materials for his execution, whereby his death was retarded for one day. At last one Somerville, a domestic of the bishop, undertook to act the part of temporal judge, and the ropes of the bishop's pavilion were taken to serve the purpose.

All things being thus prepared, he was led forth by Somerville with a guard of armed men to his execution; being come to the place, some cried out to him to recant, to whom he answered, "I marvel at your rage, ye hypocrites, who do so cruelly pursue the servants of God; as for me, I am now eighty-two years old, and cannot live long by course of nature; but an hundred shall rise out of my ashes, who shall scatter you, ye hypocrites and persecutors of God's people; and such of you as now think yourselves the best, shall not die such an honest death as I now do; I trust in God, I shall be the last who shall suffer death, in this fashion, for this cause in this land." Thus his constancy increased as his end drew near. Being ordered by Oliphant to go up to the stake, he refused, and said, "No, I will not go, except thou put me up with thy hand, for by the law of God I am forbidden to put hands to myself, but if thou wilt put to thy hand, and take part of my death, thou shalt see me go up gladly." Then Oliphant putting him foreward, he went up with a cheerful countenance, saying, Introibo ad altare Dei, and desired that he might be permitted to speak to the people; he was answered by Oliphant, "That he had spoken too much already, and the bishops were exceedingly displeased with what he had said." But some youths took his part, and bid him say on what he pleased; he first bowed his knees and prayed, then arose and standing upon the coals addressed the people to this effect, "Dear friends, the cause why I suffer this day, is not for any crime laid to my charge, though I acknowledge myself a miserable sinner before God, but only for the defence of the truths of Jesus Christ set forth in the old and new Testament; I praise God that he hath called me among the rest of his servants, to seal up his truth with my life; as I have received it of him, so I again willingly offer it up for his glory, therefore, as ye would escape eternal death, be no longer seduced with the lies of bishops, abbots, friars, monks, and the rest of that sect of Antichrist, but depend only upon Jesus Christ and his mercy, that so ye may be delivered from condemnation."—During this speech, loud murmurs and lamentations were heard among the multitude, some admiring the patience, boldness and constancy of this martyr, others complaining of the hard measures and cruelty of his persecutors. After having spoken as above, he prayed a little while, and then was drawn up and bound to the stake, and the fire being kindled, he cried, "Lord, have mercy on me; Pray, pray, good people, while there is time." And so cheerfully yielded up his soul into the hands of his God on the twenty-eighth of April, anno 1558, being then about the eighty-second year of his age.

The fortitude and constancy of this martyr affected the people so much, that they heaped up a great pile of stones on the place where he had been burned, that the memory of his death might be preserved, but the priests gave orders to have it taken down and carried away, denouncing a curse on any who should lay stones there again; but that anathema was so little regarded, that what was thrown down in the day-time was raised again in the night, until at last the papists carried away the stones to build houses in or about the town, which they did in the night, with all possible secresy.

The death of this martyr brought about the downfal of popery in Scotland, for the people in general were so much inflamed, that resolving openly to profess the truth, they bound themselves by promises, and subscriptions of oaths, That before they would be thus abused any longer they would take arms, and resist the papal tyranny, which they at last did.