Need help ASAP!! Thank you :) Duke defeated the Muslim forces at Covadonga in 722 AD and
planted the seed for the Kingdom of Asturias in North Western
Spain.

I'll assume you are requesting about the battles that led to this event.

In 722 AD, Muslim forces under the command of Al Qama and Munuza marched into and overran most of Asturias. Pelagius and his christian army retreated into the mountain of Asturias and positioned themselves in a valley bordered by mountains to its sides. Legend has it that Pelagius had as few as 300 men and the mountain was strategic in preventing a full broad frontal attack by the enemy. When Al Qama and his army arrived at this valley, Al Qama tried to bargain a surrender from Pelagius and his army but was turned down, and he proceeded into attacking Palegius' army. At the heat of the battle, Palegius who already had some of his men hidden within the mountains, personally led these other men to join the attack, resulting in Al Qama's soldier breaking rank and retreating in defeat; Al Qama himself was killed in this battle. The effect of this was that the villagers of Al Qama came out in arms and attacked the retreating soldiers, leading to a massacre of Al Qama's army . After this defeat, Munuza organised a second force and attacked again in a battle at a town near the modern day Proaza. This battle also resulted in a victory for Pelagius and resulted in the death of Munuza.

immigrants from northern and western europe continued coming as they had for three centuries, but in decreasing numbers

i do not know? i think i have seen this before though h?