The creed we use today was first formulated in the fourth century as a response to a great controversy in Christendom about the nature of the Son of God. Some said that the Son of God is a creature like everything else made by God.
Others contended that the Son of God is eternal, divine, and uncreated. Many councils met and made many statements of faith about the nature of the Son of God, but the controversy continues to rage.
The First Ecumenical Council
Finally in the year 325 Emperor Constantine called a council held in the city of Nicea which produced the profession of faith that was ultimately accepted by the Orthodox Church. This council is now called the first ecumenical council. Here is what was said:
We believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible. And in one Lord Jesus Christ, the Son of God, the only-begotten, begotten of the Father before all ages. Light of Light; true God of true God; begotten, not made; of one essence with the Father, by whom all things were made; who for us men and for our salvation came down from heaven, and was incarnate of the Holy Spirit and the Virgin Mary, and became man. And He was crucified for us under Pontius Pilate, and suffered, and was buried. And the third day He rose again, according to the Scriptures; and ascended into heaven, and sits at the right hand of the Father; and He shall come again with glory to judge the living and the dead; whose Kingdom shall have no end.
The Second Ecumenical Council
Once that debate was finished, there quickly rose another dispute about the Holy Spirit. Following another council, this time in Constantinople in 381, the following text was added to the Nicene statement:
And [we believe] in the Holy Spirit, the Lord, the Giver of Life, who proceeds from the Father; who with the Father and the Son together is worshipped and glorified; who spoke by the prophets. In one Holy, Catholic, and Apostolic Church. I acknowledge one baptism for the remission of sins. I look for the resurrection of the dead, and the life of the world to come. Amen.
You will notice that the "filioque" is no where to be seen. This extra bit of text, "and the Son" was added to the "procession" passage 600 years or so after the Second Ecumenical Council and is not accepted by the Orthodox Church.