Answer 1
It is difficult to name a single person who started radical Islam. The problem is in some people who don't understand Islam and its spiritual sense and that Islam calls for peace and cooperation among all mankind irrelevant to their faiths, colors, nationalities, or genders. Prophet Muhammad (peace be upon him) on establishing the first Islamic state in Medina issued the Medina Decree that assured equal rights and obligation among all Medina citizens irrelevant to being Jews, Christians, Muslims, polytheists, or the like. Refer to questions below for more information.
Answer 2
It is also difficult to pinpoint where Radical Islam started because it is a heterodox philosophy. This means that there are numerous different beliefs that are only tangentially related to each other, but are all grouped under the same header. For example "flying animals" would be a group like this since bugs, birds, and bats are only tangentially related to one another.
Probably, the most famous and important group of Radical Islam are the Islamists. The first modern Islamist was Sayyid Qutb (Oct. 9, 1906-August 29, 1966) who actively advocated for Islamic values to permeate government institutions. In his view Western values were corrupt and any government based on those values should be destroyed, especially in the Islamic World. He was executed for attempting to assassinate Egyptian President Gamal Abdel Nasser after being a leading member of the Muslim Brotherhood in the 1950s and 1960s.
Your question is an ideal one. before i answer it i would like to tell you, that as a Muslim i find it slightly offensive that people (not you in particular) immediately pair the word 'radical' with 'Islam'. i am a Muslim and i assure you not radical in any way. you must understand, Islam reinforces peace above all else, one of the most important events in our history was a treaty called the treaty of hudaybiyah, it was a PEACE treaty. anybody who insists on killing innocent people for no reason whatsoever can no longer be called Muslim because they have commited murder, and a Muslim does not murder. so your question of the 'principles' of radical Islam, does not exist. Islam is not radical and thus there is no such thing as a 'radical Islam' because then it wouldn't be Islam, it would be radical. make up your mind because it cant be both. so to answer your question, there is no radical Islam. -this answer is my opinion as a Muslim.
a radical Islamic leader who reinterpreted Islam to justify violence
The Prophet Mohammad started Islam.
Islam
by all three faiths I assume you mean Christianity, Islam, and Judaism. There are only similarities between Christianity and Judaism's beginning. They both started by radical movements from God. Islam started from radical movement's by either Satan himself, or one of his demons. When Mohammad was first visited by "Gabriel", he wanted to kill himself, and he was depressed. He did not come out of the cave he had the meeting in for a few years. When biblical meetings between angels occur in the holy Bible, which Islam considers to be mostly true, the humans are awed, and are eager to do Gods will.
it was started by abraham
The Radical Islam has twisted the Holy Quran and the other Islamic sects by being selective in the quotation of certain verses about Muslims and Non-Muslims.
Pristine Islam is based on Wahhabism. It is a radical and fundamentalist religious movement based on reinterpretations of the Quran and Hadith.
it started in the early 1867s.
The answer to the question would be, Islam started 600 years after Jesus went to the heavens above. Islam actually started since Adam. The religion that all the prophets preached was ISLAM meaning TOTAL SUBMISSION TO GOD'S WILL. Simply, it started with the first man and first prophet Adam.. ___________________________________________ Islam started by start of universe creation. see question below..
He was Muhammad SallallahuAlihewasalam (PBUH) on him the Holy book Quran was Nazilled so he started Islam !
Islam started with age of Adam on earth {Islamic point of view } .