Wars with Jews
Jews were one of the main political and economic forces in Arabia. They were fewer in number but greater in influence. According to some estimates they were the riches ethnic group of peninsula at that time. They dominated the banking side of Arabic community. Unlike Quraysh of mecca who was business minded community Aus and Khazraj of medina were agriculturalists. Due to two reasons Ansar or helpers were in a subservient position in city of medina.
(i) Precarious situation of economy
(ii) Internal wars between Aus and Khazraj .(They were financially dependent on the loans provided by the Jews of Yathrib.)
Jews in medina consisted of three tribes
Bani un Nadhr
The state of medina tried to negotiate a peace treaty between Muslims and Jews of medina but this effort was futile. Jews were positioned strategically as their tribes were located in the heart of Medina. First prophet tried to candidate with them by arranging an agreement named as misaq e medina charter of medina. Jews were the dominant party in medina both financially and spiritually, after the arrival of immigrants the tide was turned against them .But their numbers were few and they could not resist the ever growing force of Muslims.
According to Muslim sources they were in a league with Quraysh, Bedouins and the discontented party. The discontented party was the pre immigration elite of medina who wanted to get rid of the newly formed state. They were not in strength or position to do it openly so they get into silent alliance with the other parties who were working against state of medina.
Expulsion of Jewish tribes from Medina
Year 624 First Banu Qaynuqawere besieged and were exiled on easy conditions after the battle of badr, abanu nazr were goldsmiths and there tools were taken as war fief
Year 625 Second was Banu an Nadhr were banished from medina but they were banned on strict terms. They were an agricultural community the land left by them were allotted tho immigrant community. Immigrant took the ownership of these newly vacant lands and were no longer dependent on Ansar
Year 627 the last remaining tribe of Banu Quraiza was in conspiracy against with state of medina in a league with Quraish, Bedouins and discontented party in medina. They were found guilty of high treason and all of their men beheaded their women and children were sold slavery and their wealth and land confiscated
Their decision was put into hand of Saad their former ally who had strong grievances against them .he was disappointed with them when he asked for their military aid in the battle of ditch but all of this was of no avail.
Jews were also present in other parts of Arabian Peninsula as they have also strongholds to the north of medina; they had strong net of citadels as in khaber.
Invasion of Khaber
In the year 628 the prophet marched with 1600 including 200 horsemen towards the stronghold of khaber .One of the Jewish colonies of Al Qamus offered some resistance to Muslims. Jews did not fight Muslims in open battle rather they preferred to shut themselves in their castles. The main reason for their failed strategy was because they never combined their forces against invading army of medina and were captured on after one by the Muslim forces
The new theocratic state was now not going to tolerate its enemies. Reasons for the expulsion of Jews were simple they were the commercial rival and military threat to the rising Muslim state of Medina. Jews were town people and were business minded community. On the other hand their rival Arabs were Bedouins who were skilled swordsmen. Arabs were used to minor skirmishes and earned their living through plunder and savagery.
This campaign put an end to strength of Jewish colonies in Arabia, this was the end one of the competitors of the state of medina, and Jews were financially the strongest part in northern Arabia. As Islam put the ban on usury which was blow to the economical empire of Jews, secondly Jews always felt kind of a monopoly on their monotheistic beliefs but after Muhammad they claimed was challenged, this made Jews hostile towards newly formed religion.