Islam was first introduced to Spain in 711 A

.D.

From 711 to 1492.

Islam civilization in all branches of science and architect was transfered to Spain and from Spain to all Euorope. Despite that, no single Spanish was forced to convert to Islam although Muslims controlled Spain for more 800 years. This is clear from the evidence that the number of Muslims remianed very small minority after these 800 years.

Muhammad died in 633 C.E.; Islam arrived in Spain in 711 C.E., meaning 78 years passed.

To be entirely fair, it was Türkic Tribes of Central Asia who spread Islam to China, but the reason that Arabs spread Islam to Spain, Sicily, and India was that they genuinely believed it to be the correct religion.