Siddhartha Gautama is the founding figure of Buddhism. He lived in the sixth and fifth centuries BCE, making him a contemporary of the famous Greek politician Pericles. He was born into wealth and nobility, which he promptly rejected and then subsequently dedicated his life to finding an end to human suffering.

Syncretism is the name given to the blending of elements from more than one religion into a distinct system of worship. Examples include the blending of Confucianism, Taoism, and Legalism in China during and after the Warring States period. Syncretism often created distinct religions (like the Cult of Saints in Latin America), by mixing longstanding and native elements of paganism with the tenets of a newly introduced major organized religion.

The First Council of Nicaea effectively ended the view of Christianity as foreign or harmful to the Roman Empire and allowed it to grow into a state-sanctioned religion, supported by a rigid structure of bishops ruling over diocese, much like the structure of Roman state designations.

Faith--the belief that there is no god but Allah and Muhammad is his Prophet--is the missing pillar here, not marriage. 

The Virgin birth is a core tenet of Christian faith. The others are all examples of practices that different factions within the Church debated. 

Muslim clerics are encouraged to marry and have families in contrast to the Catholic Church. The other four listed answers are, indeed, pillars of Islam. The fifth pillar of Islam (not listed) refers to the purity of faith. 

The Ottoman Empire was filled with believers of Judaism, Orthodox Christianity, and Islam, all monotheistic religions. The Mughal Empire was characterized by the peaceful co-existence of Muslim and Hindu believers. Ancient Greece was characterized by a polytheistic religious belief system, as were Ancient Greece and Egypt, as well as the Aztec Empire.

Mansa Musa was a devout Muslim; pilgrimage to Mecca is considered a holy commandment by many devout Muslims. Devout Christians and Jews view Jerusalem as the holiest city and the most important pilgrimage site. Mali has never had a large Hindu or Buddhist community, nor have they ever had a ruler practice either of those religions.

The use of Icons to depict saints, the messiah, and Mary became synonymous with the orthodox churches of the Byzantine and Russian Empires. Quakerism, Puritanism, and Calvinism are all branches of Protestantism that admonished the Catholic traditions of iconography that they claim broke the commandment against idol worship.

Sikhism emerged from the spread of Islamic powers into the Indian Sub-Continent. Because of its geo-political beginnings, Sikhism remains strongest in the southern part of Pakistan and Northern India where the two cultures clashed.