The immediate cause of Shahjahan's rebellion against Jehangir was that Shahjahan refused to go to Qandhar which had been besieged by the Persians. This event played a significant role in triggering the rebellion and ultimately led to the strained relationship between father and son.

The rebellion of Shahjahan against Jehangir can be understood in the context of the complex power dynamics within the Mughal court. Shahjahan, who was the third son of Jehangir, had gained significant power and influence over the years. He had successfully expanded the Mughal Empire and was known for his military prowess, which further bolstered his position within the court.

However, Jehangir grew increasingly suspicious of Shahjahan's growing power and influence. He feared that Shahjahan might pose a threat to his own rule. To counter this, Jehangir sought to curtail Shahjahan's power and assert his authority. He insulted Shahjahan in the Mughal court, attempting to undermine his standing and reduce his influence.

Amidst this tense atmosphere, a crucial event unfolded. The Persians besieged Qandhar, a strategically important city in the Mughal Empire. Jehangir ordered Shahjahan to lead an army and recapture the city. However, Shahjahan refused to comply with Jehangir's orders. This act of defiance was a clear indication of the growing rift between father and son.

Shahjahan's refusal to go to Qandhar had multiple implications. Firstly, it showcased his defiance and resistance to Jehangir's authority. Secondly, it highlighted Shahjahan's desire to assert his independence and challenge his father's control. Thirdly, it demonstrated his strategic calculation and ambition to consolidate power for himself.

This event proved to be the immediate cause of Shahjahan's rebellion against Jehangir. It deepened the existing rift between them and further fueled Shahjahan's desire for power. Shahjahan saw this as an opportunity to challenge Jehangir's authority and secure his own position as the rightful heir to the throne.

In conclusion, the immediate cause of Shahjahan's rebellion against Jehangir was his refusal to go to Qandhar, which had been besieged by the Persians. This event marked a significant turning point in their relationship and set the stage for the subsequent power struggle within the Mughal court.