There are two forms of the Paraklesis Canon to the Theotokos: the Small Paraklesis which was composed by Theosteriktos the Monk in the 9th century (or some say Theophanes), and the Great Paraklesis. During the majority of the year, only the Small Paraklesis to the Theotokos is chanted. However, during the Dormition Fast (August 1—14), the Typikon prescribes that the Small and Great Paraklesis be chanted on alternate evenings, according to the following regulations:
– If August 1st falls on a Monday through Friday, the cycle begins with the Small Paraklesis. If August 1st falls on a Saturday or Sunday, the cycle begins with the Great Paraklesis.
– On the eves of Sundays (i.e., Saturday nights) and on the eve of the Transfiguration (the night of August 5) the Paraklesis is omitted.
– On Sunday nights, the Great Paraklesis is always used unless it is the eve of Transfiguration.
The reason these services are called “Paraklesis” (Supplication) is because the faithful gather to supplicate the Theotokos to intercede on their behalf to her Son and our God for our salvation and for the relief of anything that burdens and ails us. They are the prayers of suffering and hurting children addressed to their compassionate Mother, who is their only hope, protectress, and surety in time of need.
According to liturgical Professor John Fountoulis, even though the two Canons to the Theotokos are differentiated with the title “Small” and “Great”, in fact they have the same number of Troparia, both having thirty-two with four in each Ode. However, the Great Canon is more extensive, though this does not justify the epithet. The real reason seems to be that the Great Canon is chanted in a more festive tone during the Dormition Fast than the Small Canon, as shown in the Dismissal Hymns which begin:
“O you Apostles from afar, being now gathered together here in the village of Gethsemane, lay my body in burial; and You, my Son and my God, receive my spirit.”
Little research has been done on the historical circumstances that led to the poetry of the two Canons and the final morphology of the two Supplications.
Regarding the Great Supplication Service, we have sufficient testimony to its authorship. The poet was Theodore II Doukas Laskaris, Emperor of Nicaea. He was an emperor in exile who reigned from 1254 to 1258 AD following the fall of Constantinople to the Frankish Crusaders in 1204.
The Small Supplication Service is older than the Great Supplication Service and its authorship is attributed by some to Theosteriktos the Monk, who lived in the ninth century. Others speculate it to be the work of Metropolitan Theophanes the Confessor of Nicaea who lived in the same century. Some even put forward St. John the Damascene as the composer.
In the liturgical book Horologion it simply states as the author: “A poem of Theosteriktos the Monk. Others support Theophanes.” Some say that these two names actually belonged to the same person; Theophanes was the name of Theosteriktos before he became a monk.
~Adapted from Mystagogy: The Weblog of John Sanidopoulos (http://www.johnsanidopoulos.com/2011/08/history-of-small-paraklesis.html)