The Ghassanids, who successfully oppose the Persian-oriented Lakhmids of al-Hirah, prosper economically and engage in much religious and public building; they also patronize the arts and entertain the poet Nabighah adh-Dhubyani and, later, Hassan ibn Thabit at their courts.

Subsequent Roman distrust of Ghassanid religious unorthodoxy brings down al-Harith's successors, al-Mundhir and Nu'man.

(According to one story, which seems to be supported by Nabighah's later poetry, his enemies forged a satire against Nu'man, who was so enraged that Nabighah had to leave al-Hirah in great haste.)

Nabighah moves from Jabiyah to the enemy court of the Ghassanids in Syria, where he becomes a favorite, interceding several times on behalf of his tribesmen during their wars and defeats.

He never ceases to assert his innocence to Nu'man and eventually returns to al-Hirah.

Orthodox leaders of the Eastern Roman empire, viewing the Monophysite beliefs of the the Arab Ghassanids to be unacceptably heretical, reduce Ghassan to vassal status and dispatch imperial troops to secure its borders.

Two of the wives of Lakhmid king Al-Mundhir IV ibn al-Mundhir are known by name: the Jewish captive Salma bint al-Sa'igh, the mother of his heir Nu'man, and the Christian Mariya bint al-Harith ibn Djulhum.

Mundhir is known to have had twelve or thirteen sons.

He is succeeded in 580 by his son al-Nu'man III ibn al-Mundhir (r. 580–602), the last Lakhmid king of Hirah.

Al-Hirah begins to decline early in the sixth century, the Persians having brought about the collapse of the Lakhmid dynasty.

Al-Nu'man III ibn al-Mundhir, the son of Al-Mundhir IV ibn al-Mundhir and the enslaved Salma or Sulma, had succeeded his father in 580.

In later histories, he is celebrated for his patronage of numerous poets.

He is also the only Lakhmid ruler to convert to Nestorian Christianity.

According to Arab accounts, he assisted Khosrau II during his flight from the usurper Bahram Chobin in 581.

Nevertheless, according to creditable historical accounts, when Khosrau II demanded Nu'man's Christian daughter as part of his extensive harem, he refused the Shah's demand.

In response, Khosrau II had him crushed by elephants; however, according to a Syriac chronicle, Khosrau invited Nu'man to a feast where he was dishonored and trapped; another Syriac chronicle states that Khosrow captured Nu'man along with his sons, who then were poisoned.

This is the spark that will lead to the Battle of Dhi Qar in 609.

His destiny after his arrival at Ctesiphon is largely disputed, even in near-contemporary sources; he was either immediately executed or imprisoned for a period of time and then executed, but in 609 he was certainly dead and Iyas his ex-friend was installed, marking the end of the dynasty, although Nu'man's son al-Mundhir will attempt to revive the kingdom during the Ridda wars and will rule the Bahrain region for a short period of eight months until he is captured.

Al-Nu'man III ibn al-Mundhir is celebrated in later histories for his patronage of numerous poets.

He is also the only Lakhmid ruler to convert to Nestorian Christianity.

According to Arab accounts, he had assisted Khosrau II during his flight from the usurper Bahram Chobin in 581.

Nevertheless, according to creditable historical accounts, when Khosrau II demanded Nu'man's Christian daughter Hadiqah as part of his extensive harem of three thousand wives and twelve thousand female slaves, demanded as a wife Hadiqah, the daughter of the Christian Arab Na'aman, Na'aman refused to permit his Christian daughter to enter the harem of a Zoroastrian; for this refusal, he was trampled to death by an elephant.

However, according to a Syriac chronicle, Khosrau invited Nu'man to a feast where he was dishonored and trapped; another Syriac chronicle states that Khosrow captured Nu'man along with his sons, who then were poisoned.

This is the spark that will lead to the Battle of Dhi Qar in 609.

The fate of the deposed Lakhmid king Al-Nu'man III ibn al-Mundhir after his arrival at Ctesiphon is largely disputed, even in near-contemporary sources; he was either immediately executed or imprisoned for a period of time and then executed, but in 609 he is certainly dead and his former friend Iyas ibn Qabisah al-Ta'i, an Arab of the tribe of Tayy, has been installed, marking the end of the dynasty, although Nu'man's son al-Mundhir will try to revive the kingdom during the Ridda wars (632-33) and will rule the Bahrain region for a short period of eight months until he is captured.

At an indeterminate date, an open clash between the Persians and their Arab auxiliaries, on one hand, and Arab tribesmen, on the other, occurs at Dhi Qar.

According to certain Muslim traditions, the battle took place in the year 623 or 624.

Modern scholars have narrowed this range to 604-11.

Arab sources number the Persian force at two thousand soldiers, with three thousand Arabs led by Iyas ibn Qabisah.

The Arab force opposing the Persians, with their Arab auxiliaries, is from the Bakr ibn Wa'il, a large tribal confederation whose territory extends from southwestern Iraq into the eastern Arabian peninsula.

The most prominent constituent tribe is the Banu Shayban, the other groups being the Banu 'Ijl, Banū Zohl, Banu Qays ben Thalaba, Banu Taym Allah ben Thalaba, and Banu Yashkor.

These groups do not seem to have coordinated their efforts on the battlefield, nor did they have a single commander in chief.

Rather, leadership seems to have shifted among various warriors.

Nevertheless, the Banu Bakr defeat the combined Persian and Arab forces.

Some scholars, apparently influenced by the Muslim tradition, have interpreted the battle of Dhi Qar as part of a prolonged Arab rebellion against the Persians, which culminated in the Muslim conquest of the Persian empire.

As Shaybani tribesmen, led by Mosannā ben Haresa, assisted in the conquest of Iraq, it has been argued that the Bakr, and especially the Shayban, had followed a distinct anti-Sasanian policy since Dhi Qar.

Scholars have shown, however, that the Shayban who supported the Muslims and those who were prominent at Dhi Qar belonged to different, even rival clans; some Shaybani leaders allied themselves with the Persians after Dhi Qar, and others even opposed the Muslims during the conquest of Iraq.

The battle of Dhi Qar thus appears to have had ideological and symbolic meaning for the Arabs far beyond its military and political significance.