Daniel Alekseevich Sysoyev was born on January 12, 1974, to Alexsei Nikolaevich Sysoyev and Anna Midkhatovna Amirova, within a family of teachers and artists. He was later baptised on October 31, 1977 in Vorobyovy Hills. He attended church with his family, assisting in the altar and in the choir at the church where his father was sacristan. 
In the summer of 1988, Daniel helped in restoration work at Optina monastery. When the church at the former Novoalekseev Monastery began, Daniel sang in the choir. The rector recommended that the young Daniel enter Moscow Theological Seminary. This he did, after completing secondary school in 1991. 
Seminarian and Deacon
Fr Daniel studied in Moscow Theological Seminary , where he had the obedience of choir singer and of leading a mixed choir.
In 1993, he describes the beginning of his missionary work on the streets. 
He was tonsured a reader on December 19, 1994 by Bishop Rostislav of Magadan and Chukotka, beginning a series of great changes. Rdr Daniel was married to Iulia Mikhailovna Brykina on January 22, 1995, by Fr Dionisy Pozdnyaev; in May 13, Bishop Evgenii of Verey ordained him as deacon. Dcn Daniel graduated from Moscow Theological Seminary at the top of the class on June 14, 1995, with his first child being born later that year. He subsequently enrolled in the correspondence course of the Moscow Theological Academy, and was assigned to the Bulgarian metochion church of the Dormition of the All-Holy Mother of God in Gonchary, where he taught the Law of God senior classes of the Iasenevo Orthodox Classical Gymnasium (high school).
From August 1996, the Patriarch blessed him to hold missionary Biblical conversations in the Kriutitsy Patriarchal Metochion with people who had suffered from the influence of sects and, later, occult activities. He began work at the Rehabilitation Centre of St John of Kronstadt, under the direction of Hmk Anatoly (Berestoy).
In 1999, Dcn Daniel published his first book, entitled The Chronicle of the Beginning, which was published by Sretensky Monastery and dedicated to the patristic doctrine of creation. On May 24, 2000, he was awarded a letter of commendation for teaching by the Department of Religious Education and Catechesis; in June of that year, the council of the Moscow Theological Academy approved his thesis, Anthropology and Analysis of the Seventh Day Adventists and the Watchtower Society, and Dcn Daniel graduated. In the same year, Hexaemeron Against Evolution, edited by Dcn Daniel, was published.
Priest and Missionary
In 2001, he was ordained to the priesthood, and his second child was born. He was assigned to the Church of Sts Peter and Paul in Yasenevo, Moscow, where he became secretary of the Shestodnev missionary-educational centre and continuing his work at the St John of Kronstadt centre. Around this time, his anthology on Divine Revelation and Contemporary Science was published; over his lifetime, he would publish over a dozen articles on creation and anti-sectarian issues.
Fr Daniel was soon transferred to be the rector of the Church of the Apostle Thomas, where he initiated a growing community in honour of the Prophet Daniel. One of the goals of this centre was the conversion of non-Christians, mostly non-Russians. This is particularly the case as the Kantemirovskiy district in Moscow, where the is a district of many expatriate communities, and where many different sects are active, including Baptists, Mormons, Adventists and occultists. Until Fr Daniel came, there was no Orthodox centre. He also opened a catechetical school about the basics of Christianity, and ran a successive five-week catechetical discourses for those who wished to know more about Christianity (for baptism or for interest). In time, a community of Orthodox Tartars (began in 2003) built up, and the information agency of St Akhmet began activity. Fr Daniel's church had initiatives such as an open house, where the church would be open and the priest available for questions. Molebens were frequent, particularly for conversion of the non-Orthodox, and also for students at the nearby Moscow Engineering and Physical University. Fr Daniel later began to offer missionary courses, preparing preachers of the Gospel.
As rector of St. Thomas' church in southern Moscow, Fr Daniel was a noted missionary, especially among the Muslim, neo-Pagans, and Protestants communities of Russia. As the Orthodox Church in Russia has come around to the importance of missionary work in recent years, Fr. Daniel became known for his active missionary work, particularly among non-Orthodox, and also for his bright polemic performances. He had especially built a reputation as a priest who stood out for his proselytizing work among Russia’s Muslim community, baptising around eighty Muslims .
His initiatives included other non-Orthodox communities. Fr. Daniel was noted for promoting a number of cultural and religious initiatives among Chinese students in Russia. 
As a result of his preaching, Fr Daniel received fourteen death threats .
On November 19, 2009, he was killed in his church by a Muslim fanatic, who shot him four times. Fr Daniel was 34 years old. During the last 19 years Fr. Daniel became the twenty fifth Orthodox priest murdered in Russia.
Later, in December 2009, a militant Islamic group based in the North Caucasus took credit for the murder of Fr. Daniel. According to a statement made by Russian Islamists and released on kavkazcentre.com:
- "One of our brothers who has never been to the Caucasus took up the oath of (former independent Chechen president Doku Umarov) and expressed his desire to execute the damned Sysoyev"
Mother Prosdokia, abbess of the Ormylia convent in Greece, stated that "it is time to not to pray for Fr Daniel, but to pray to him", expressing that he is a saint. Many Orthodox in Greece venerate Fr Daniel in a similar manner to those martyred during Turkish occupation of Greece. 
- ↑ AsiaNews.it. Orthodox missionaries for Chinese students in Moscow. April 15, 2010.
- ↑ Sophia Kishkovsky. Russian Priest Killed in Church. The New York Times. November 19, 2009.
- ↑ Islamists claim killing of Russian priest. AFP. Dec. 25, 2009.
- ↑ Patriarch Cyril calls the priest Daniel Sysoeva confessor and martyr of the faith. Interfax-Religion. November 20, 2009.
- Kevin O'Flynn. Murder Of Priest Highlights Missionary Role In Russian Church. Radio Free Europe / Radio Liberty. December 01, 2009.
- The funeral of the Priest Daniil Sysoyev passed in Moscow. Interfax-Religion. November 23, 2009.
- Patriarch Kirill urges believers to think about importance of missionary outreach. Interfax-Religion. November 23, 2009.
- Patriarch Cyril calls the priest Daniel Sysoeva confessor and martyr of the faith. Interfax-Religion. November 20, 2009.
- Council of Muftis expresses condolences on priest's murder. Interfax-Religion. November 20, 2009.
- Moscow priest could have been killed by extremists, pagans – sources. Interfax-Religion. November 20, 2009.
- Patriarch Kirill offers condolences over death of the priest. Interfax-Religion. November 20, 2009.
- Famous Orthodox priest killed in Moscow. Interfax-Religion. November 20, 2009.
- Fr. Daniel's blog in LJ
- AsiaNews.it. Orthodox missionaries for Chinese students in Moscow. April 15, 2010.
- The missionary movement associated with Fr Daniel Sysoyev (“Prophet Daniil movement”) is promoting a number of cultural and religious initiatives among Chinese students in Russia.