Well, the Catechism in the 1662 prayerbook didn't mention Matrimony at all. I think a weakness of the 1979 prayerbook is that it is trying to include too much in what should be a basic summary of the faith, at the level of essentials. The 1662 has the details and definitions about marriage in the rubrics and content of the marriage service itself. The other place I recall the 1662 mentioning Matrimony is in Article 25, in which it states that Matrimony is not to be counted a Sacrament.

It's important to note that the original question of this thread is "What is Holy Matrimony" not "what is Marriage". Marriage is an cultural and anthropological distinction defining the way that non-related adults form into family groupings within a culture. In different cultures marriage does take different forms. In terms of social anthropology, marriage has several dimensions: legal, social, religious, and economic.

In Canada, to take a familiar developed-world, western example, common-law marriage has full legal force, enjoys all economic factors of other marriage except inheritance law, and is socially acceptable to the degree that it is indistinguishable from other forms of marriage. And frankly, given the nature of Canada's taxation laws, a common-law marriage where one partner is not working enjoys better economic recognition at tax-time, than a registered marriage where both partners work. The one difference I see between common-law marriage and a marriage celebrated by a Priest or Deacon using a valid service, is in its religious dimension -- in many cases common-law marriage is not Holy Matrimony.

But that same consideration applies to marriages effected in the marriage commissioner's office, even though they are recorded in the register. We have to wonder as well, if a church firmly denies that their marriages have any sacramental force and the pastor merely acts as a marriage commissioner himself -- say a marriage in an Evangelical Free church -- whether that marriage is Holy Matrimony, or just a secular marriage administered by a church official.

And that chain of thought raises the question as whether a couple, not having been to church since their grandmother brought them to the baptismal font as infants to "have them done", and not planning to return again until the same grandma's funeral demands their presence, can be truly said to be confecting "Holy Matrimony" when they go through the motions in an Anglican church without understanding any religious dimension to what is happening there. They get a great traditional location, and the stained glass makes a great background for their wedding photo album -- but did they get Holy Matrimony?

Be ye kind, one to another.

Okay, Dave. I'm going to try to take this on. God grant that I don't put my foot in it too badly.

As Father Rick says, a marriage has a dimension of contract law to it. A contract is formed when both parties offer 'consideration' (make reciprocal commitments of some sort). The contract is enforceable only if it is allowed by law.

In Canada, your marriage is legal if it is performed by a marriage commissioner according to the law, which varies slightly from province to province. In Ontario, it is perfectly legal to be married by banns, with no license. In Quebec, the only legal marriage is a civil marriage by contract -- the religious ceremony must be performed separately. Or a common-law arrangement is a legal marriage if it lasts for longer than a year, provided that you are otherwise free to marry -- that is, not legally married to someone else. So, it is perfectly possible to have a legal marriage that has no ceremony or license.

Now, the legal dimension is not the only dimension to marriage. Marriage of course has a cultural dimension as well. You can think of this as "will the people with whom I socialize treat my partner and me as married" or as "will wedding invitations sent to us have both our names on the same line". This will vary with social strata. Some people will not recognize common-law marriages even though they are legal. Other people will recognize common-law relationships that haven't lasted as much as month, let alone a year.

But you asked specifically about the religious dimension of Marriage.

As Fish and Bread said, Anglicans don't have unequivocal consistent doctrine about marriage. Some of us believe that marriage is a sacrament -- an outward and visible sign of an inward and spiritual grace, given by God. But the question of what the outward and visible sign has different answers. Some would say it is the declaration of the minister (who need not be a priest: deacons can perform marriages) "I pronounce that they be man and wife together". Others would say it is "the giving and receiving of a ring", or exchanging the words of the wedding vows. My priest explained that it is the act of physical intimacy that is the "outward and visible sign" of marriage, the inward and spiritual grace being 'the two becoming one flesh' at a spiritual level.

In all of these conceptions of the 'outward and visible sign' save the first, it is the husband and wife that effect the sign of the marriage; that 'confect' the marriage sacrament. The priest represents the Church, since all sacraments were given to the Church for the building up of the Body of Christ. So it is appropriate that a priest be present. One or two other members of the Body are also required, because the priest cannot function as "Church" alone -- there must be 'two or three gathered together in Christ's name'. But it is the man and woman who "marry" each other.

In fact, well into the eighteenth century in Scotland, a legal Christian marriage could be confected by the husband and wife declaring before any Christian witness, first that there was no impediment to marriage, and second the simple vow "I, name, take, you name, as my husband/wife, in the name of the Father, and of the Son, and of the Holy Ghost".

This quote is not part of our historic wedding ceremony. Whether the marriage were confected or not by this point, depends on the order of service in question. If any impediment existed to the marriage (consanguinity, monastic vows, or prior marriage) or if either the husband or the wife did not state aloud the marriage vows, then the marriage was not effected.

If the couple are already separated, then the existance of the marriage becomes moot, does it not? The children's interests are protected by the fact that, whether or not the parents were ever husband and wife, they are both unarguable parents. They both have the duty of ensuring the physical, emotional and spiritual well-being of the children.

The only issue affecting the children that could be altered by a marriage's having existed, is whether they are illegitimate or not. Illegitimacy is a legal matter, not a theological matter. The Church doesn't even address the matter: within the Church, all of us have the same Father, and he acknowledges all of us as legitimate through our Baptisms.

The only other issue affected by determining whether a sacramental marriage existed in the past, separate from the legal or cultural aspects of marriage, would be whether the partners are free to marry again. That could be quite a burden upon someone's conscience, if they wanted to marry but were afraid that in the eyes of God they might be already married. If that were the case, the person should take that concern to confession, or at least to counselling with their priest.