I believe that the correct answer would be either Abraham of Rostov, who died between 1073 and 1077; or Antony (Anthony) of the Caves, who died in 1073. Both appear in the list of Catholic saints, and both are venerated in the Eastern Orthodox Church.
Abraham is known as Abraham the Wonderworker in the Orthodox Church, where he is remembered on October 29. His life is described:
Saint Abramius, Archimandrite of Rostov, in the world Abercius, left
his parents’ home in his youth and entered upon the path of Christian
asceticism. Having assumed the monastic schema, Abramius settled at
Rostov on the shore of Lake Nero. In the Rostov lands there were not
many pagans, and the saint worked intensely at spreading the true
Not far from the cell of the saint was a pagan temple, where the
pagans worshipped a stone idol of Veles (Volos), which caused fright
among the inhabitants of Rostov. In a miraculous vision the Apostle
John the Theologian stood before Abramius, and gave him a staff with a
cross on top, with which the venerable one destroyed the idol. At the
place of the pagan temple, St Abramius founded a monastery in honor of
the Theophany and became its head.
In memory of the miraculous appearance, the holy monk built a church
named for St John the Theologian. Many of the pagans were persuaded
and baptized by St Abramius. Particularly great was his influence with
the children whom he taught the ability to read and write, instructing
them in the law of God, and tonsured monastics from among them.
Everyone who came to the monastery was accepted with love. The saint’s
life was a constant work of prayer and toil for the benefit of the
brethren: he chopped firewood for the oven, he laundered the monks’
clothing and carried water for the kitchen. St Abramius reposed in old
age and was buried in the church of the Theophany.
His holy relics were uncovered in the time of Great Prince Vsevolod
(1176-1212). In the year 1551, Tsar Ivan the Terrible, before his
campaign against Kazan, made the rounds of holy places. At the
Theophany-Abramiev monastery the monks showed him the staff with which
St Abramius had destroyed the idol of Veles. The Tsar took the staff
with him on the campaign, but the cross remained at the monastery. And
returning again after the subjugation of the Khan, Ivan the Terrible
gave orders to build a new stone church at the Abramiev monastery in
honor of the Theophany, with four chapels, and he also supplied it
with books and icons.
The life of Antony of the Caves is described:
Saint Anthony of the Kiev Caves was born in the year 983 at Liubech,
not far from Chernigov, and was named Antipas in Baptism. Possessing
the fear of God from his youth, he desired to be clothed in the
monastic schema. When he reached a mature age, he wandered until he
arrived on Mt. Athos, burning with the desire to emulate the deeds of
its holy inhabitants. Here he received monastic tonsure, and the young
monk pleased God in every aspect of his spiritual struggles on the
path of virtue. He particularly excelled in humility and obedience, so
that all the monks rejoiced to see his holy life.
The igumen saw in St Anthony the great future ascetic, and inspired by
God, he sent him back to his native land, saying, “Anthony, it is time
for you to guide others in holiness. Return to your own Russian land,
and be an example for others. May the blessing of the Holy Mountain be
Returning to the land of Rus, Anthony began to make the rounds of the
monasteries about Kiev, but nowhere did he find that strict life which
had drawn him to Mt. Athos.
Through the Providence of God, Anthony came to the hills of Kiev by
the banks of the River Dniepr. The forested area near the village of
Berestovo reminded him of his beloved Athos. There he found a cave
which had been dug out by the Priest Hilarion, who later became
Metropolitan of Kiev (October 21). Since he liked the spot, Anthony
prayed with tears, “Lord, let the blessing of Mt. Athos be upon this
spot, and strengthen me to remain here.” He began to struggle in
prayer, fasting, vigil and physical labor. Every other day, or every
third day, he would eat only dry bread and a little water. Sometimes
he did not eat for a week. People began to come to the ascetic for his
blessing and counsel, and some decided to remain with the saint.
Among Anthony’s first disciples was St Nikon (March 23), who tonsured
St Theodosius of the Caves (May 3) at the monastery in the year 1032.
The virtuous life of St Anthony illumined the Russian land with the
beauty of monasticism. St Anthony lovingly received those who yearned
for the monastic life. After instructing them how to follow Christ, he
asked St Nikon to tonsure them. When twelve disciples had gathered
about St Anthony, the brethren dug a large cave and built a church and
cells for the monks within it.
After he appointed Abbot Barlaam to guide the brethren, St Anthony
withdrew from the monastery. He dug a new cave for himself, then hid
himself within it. There too, monks began to settle around him.
Afterwards, the saint built a small wooden church in honor of the
Dormition of the Mother of God over the Far Caves.
At the insistence of Prince Izyaslav, the igumen Barlaam withdrew to
the Dimitriev monastery. With the blessing of St Anthony and with the
general agreement of the brethren, the meek and humble Theodosius was
chosen as igumen. By this time, the number of brethren had already
reached a hundred men. The Kiev Great Prince Izyaslav (+ 1078) gave
the monks the hill on which the large church and cells were built,
with a palisade all around. Thus, the renowned monastery over the
caves was established. Describing this, the chronicler remarks that
while many monasteries were built by emperors and nobles, they could
not compare with those which are built with holy prayers and tears,
and by fasting and vigil. Although St Anthony had no gold, he built a
monastery which became the first spiritual center of Rus.
For his holiness of life, God glorified St Anthony with the gift of
clairvoyance and wonderworking. One example of this occurred during
the construction of the Great Caves church. The Most Holy Theotokos
Herself stood before him and St Theodosius in the Blachernae church in
Constantinople, where they had been miraculously transported without
leaving their own monastery. Actually, two angels appeared in
Constantinople in their forms (See May 3, the account of the Kiev
Caves Icon of the Most Holy Theotokos). Having received gold from the
Mother of God, the saints commissioned master architects, who came
from Constantinople to the Russian land on the command of the Queen of
Heaven to build the church at the Monastery of the Caves. During this
appearance, the Mother of God foretold the impending death of St
Anthony, which occurred on July 10, 1073.