Of course, No
Constantine himself was not Muslim.
The prophet of Islam religion is prophet Muhammad (PBUH) to whom God revealed Quran, Muslims holy book, through the angel Gabriel (Jibril).
No Muslim figure is holy per Islam teachings. However, prophet Muhammad is the prophet of Islam religion per God Quran revelation to him through the angel Gabriel (Jibril)
The Sunnat is applied to the actions of the Holy Prophet (SAW) while Hadith is applied to the sayings of the holy Prophet (SAW)
According to the teachings of the holy Qur'an and the sayings of the holy Prophet Hazrat Muhammad (s.a.w.) the Muslims believe that Hazrat Muhammad (s.a.w.) is the last Prophet of islam and the QUR'AN IS THE LAST heavenly book.
Islam always follow what is mentioned in the Holy Quran and what Prophet Mohammad have said (Hadeeth).
The holy book of Islam is Quran that reflects real God revelation to prophet Muhammad; peace be upon him; through the angel Jibril (or Gabriel). Besides the Quran, there is the Prophet Hadith (prophet sayings and practices)
Quran is the holy book of Islam per prophet Muhammad (peace be upon him). It is holy because it reflects real Allah (or God and same God in Christianity and Judaism) words revelation to prophet Muhammad through the angel Gabriel (or Jibril).
There are so many holy men in Islam. All the Prophets (May peace be upon them all) are considered holy by the Muslims. Te holiest Personality in Islam is Hazrat Muhammad (SAW), the last prophet of Islam.
Mohammed, the final Islamic prophet was Islam's first leader.
Understanding the teachings of Islam and following the commands of Almighty Allah and the holy Prophet (SAW).
The Qur'an is the holy book of Islam, which is the religion followed by Muslims. It is believed to be the literal word of God as revealed to the Prophet Muhammad.
Prophet Muhammad lived there and the Ka'bah, a holy site/building is in Makkan
The most sacred text of the Muslims is the holy Qur'an, that is the word of Almighty Allah revealed to the last Prophet of Islam (SAW).The collections of the sayings of the holy Prophet (SAW) are also sacred books of the Muslims.