The betrothal ceremony takes place first as shown here.
In this betrothal ceremony as in the Orthodox Tradition, the servant of God Justin is betrothed to the handmaiden of God Anna and the handmaiden of God is betrothed to the servant of God Justin in the name of the Father, Son and the Holy Spirit Amen..
This is repeated three times - with more detail of the betrothal and ceremony documented here where everything happens for a reason, even if not always entirely clear.
The following is the condensed version of this wedding union
The Greek Orthodox Archdiocese of America - Office of Interfaith Marriage website writes:.
'From an Orthodox perspective, sacraments are God-given gifts that have emerged from Holy Tradition, and have either been instituted by Christ or the Apostles. Orthodox Tradition also refers to them as mysteries. That is because a dimension these experiences is tangible and can be explicated, and another part must be accepted by faith.
The sacraments are best understood as God-given points of contact, where God makes Himself available to us on a very personal level. Moreover, as we choose to faithfully participate in these mysteries, God’s life giving, life changing grace touches our lives and, by extension, makes us holy.
Historical and Theological Information
The Sacrament of Marriage is comprised of two interrelated parts – the Betrothal Service, and the Crowning Service.'
If we consider the betrothal of a bride to her groom in the Jewish Orthodox wedding, the betrothal ceremony is also very important in the Orthodox Christian wedding. The crowns are placed on the bride and grooms heads - each one connected by a tape of white ribbon. This symbolises the union of two souls in a ceremony in a royal wedding of the servant and handmaiden of God.
Peace be with you