Grand Prince Inpyeong (1622–1658) was the third son of King Injo of Joseon.
After the death of Grand Prince Neungchang, Inpyeong became his adopted son.
Officials argued that Inpyeong is trying to get hospitality by visiting Qing Dynasty a lot.
Song Si-yeol was angry how Hyojong was against his father's advice of taking care of Inpyeong but, sending him as an ambassador to the tiger cave(which meant Qing dynasty).
[4] Hyojong weeped for his dead which made him to stay at Inpyeong's house too long to make his officials to come back to the palace.