I suppose it depends on your definition of ‘diverse’. There’s geographically diverse marriages, where the bride and groom came from opposite sides of the (at the time) known world, and then there’s “exotic”, ie inter-religious, interethnic, interracial, etc. marriage.
Arranging a royal marriage was a complicated process! Generally, you wanted to arrange a match that would be politically expedient, with someone of the highest possible status and prestige, with a good probability of producing legitimate heirs to the throne, and that would cause the fewest complications politically and religiously. Some of the scheming that went on would put the Bene Gesserit from Dune to shame. That being said, due to exceptional circumstances, some exceptional pairings did occur.
I would say that for most exotic and diverse, the best place to look would be some of the marriages that took place within the Mongol descendants of Genghis Khan. The Mongols often married nobles from subjugated lands, and also sent Mongol princesses to marry client-kings.
GOLDEN HORDE and the BYZANTINE EMPIRE
Tokhtai, khan of the Golden Horde, married Maria, illegitimate daughter of the Byzantine emperor Andronikos II.
Nogai, kingmaker of the Golden Horde, married Euphrosyne, daughter of the Byzantine emperor Mikhael VIII.
YUAN DYNASTY OF CHINA (Mongol) and KOREA
Chungnyeol, king of Goryeo, married Khudulu Khaimish, daughter of Khubilai Khan
Chungseon, king of Goryeo, son of the preceding couple, married Botasirin (great-granddaughter of Khubilai)
Chungsug, king of Goryeo, married Irinjinbala (great-granddaughter of Khubilai) and Jintong (another great-granddaughter of Khubilai; her sister Botasirin was the wife of Chungsug’s father Chungseon but not Chungsug’s mother – his mother was a lower-ranked Mongol wife named Yesujin who’s father is unknown).
IL-KHANATE OF PERSIA (Mongol) and the BYZANTINE EMPIRE
Abaka, Il-Khan of Persia, married Maria, illegitimate daughter of Byzantine emperor Mikhael VIII (her sister Euphrosyne married Nogai of the Golden Horde, above)
Sidenote: Abaka, although a Buddhist, made one of the VERY few inter-faith marriages recorded in this period for a Muslim princess, when he married Padishah of Kirman, a Persian heiress. After he died, Padishah married her stepson Ghaykhatu. Padishah’s lifelong rival was her half-brother, Jalal ad-Din Suyurghatmish, who himself was married to a a Mongol princess of the Golden Horde, Kurdudjin. After Ghaykhatu put Padishah into power in Kirman, she arrested and killed her half-brother. After Ghaykhatu’s death, his successor and cousin Baidu married Shah Alam, a daughter of Suyurghatmish and Kurdudjin. Kurdudjin, the grieving widow, convinced her son-in-law to have Padishah put to death. What goes around comes back around!
IL-KHANATE OF PERSIA (Mongol) and GEORGIA
Oljai, daughter of Abaka Khan, married two kings of Georgia in succession: Vakhtang II and Davit VIII.