What is a Deacon?
A Catholic Deacon is an ordained minister
of the Roman Catholic Church. There are three groups of
ordained ministers in the Catholic Church: Bishops,
Presbyters (priests), and Deacons. Deacons are ordained
as a sacramental sign to the Church and to the world of
Christ, who came "to serve, not be served." The entire
Church is called by Christ to serve, and the Deacon,
by virtue of his ordination and through his ministries,
is to be a servant in a Servant-Church.
(http://usccb.org/deacon/faqs.shtml)
What Do Deacons Do?
All ordained Deacons are called to the
functions of Word, Sacrament, and Charity. As ministers of the
Word, Deacons proclaim the Gospel, preach, and teach in the
name of the Church. As ministers of the Sacraments, Deacons
baptize, lead the faithful in prayer, witness marriages, and
conduct wake and funeral services. As ministers of Charity,
Deacons are leaders in identifying the needs of others, then
marshaling Church resources to meet those needs. Deacons are
also dedicated to eliminating injustices or inequities that
cause such needs.
(http://usccb.org/deacon/faqs.shtml)
It began with the seven Deacons. the historical beginning of the Deacon ministry is recorded in the Acts of the Apostles(6:1-6). At that time the number of disciples was growing fast. Friction developed between the Greek and Hebrew followers because their widows were being neglicted in the daily distribution of food. So the twelve Apostles called together the community of disciples and siad, "It is not right for us to neglect the Word of God to serve at table. Brothers, select from among you seven reputable men, filled with the Spirit of Wisdom, whom we shall appoint to the task, whereas, we shall devote ourselves to prayer and ministry of the Word." The proposal was accepted by the whole community, so they chose Stephen, a man filled with faith and the Holy Spirit, also Phillip, Prochorus, Nicanor, Timon, Parenas, and Nicholas of Antioch. They presented these men to the Apostles, who prayed and laid hands on them. The term that was used to describe Stephan and the others selected was the Greek word "diacona", which is translated as "servant" or "minister."
As you can see, the early Deacons had a key role in the life of the Church. In fact, the first martyr was Saint Stephen. In Stephen's preaching that Jesus was the Messiah, the Jews treated his proclamation as blasphemies against Moses and God. Eventually the Pharisaic zealots seized Stephen and brought him before the Sanhedrin on the charge of speaking against the temple and the Law. Stephen proclaimed, "I see the heavens opened, and the Son of Man standing on the right hand of God." Without even going through the formality of condeming him to death, the zealots dragged him out of the city and stoned him to death. For more information, see Acts 7:1-53 (Stephen's Discourse), Acts 7:54-60 (Stephen's Martyrdom), and Acts 8:26-40 (Phillip and the eunuch).
The need for Deacons diminished as time passed with Catholicism becoming the official religion of Rome, and the huge increases in priests and religious. Consequently, the Diaconate was a distinct Sacrament of Orders essentially became inactive in the Latin Church for some 1000 years. The Diaconate essentially became more of a trasitional step on the way to priesthood. However, the Eastern Rite Church continued the tradition of the permanent Diaconate.
On June 18, 1967, the Second Vatican Council restored the permanent Diaconate (Apostalic Letter: Sacrum Diaonatius Ordinem in the Latin Church. By this letter the Diaconate was restored to give depth to the ordained ministry and offical Church presence in the business world.