Final answer:
The 1800s in the Indian Ocean region saw increased colonization by Europeans, active maritime trade networks facilitating cultural exchanges, and a rise in cultural and religious diversity due to the spread of Islam.
Step-by-step explanation:
The 1800s were marked by significant changes within the Indian Ocean region. One major development was the increased colonization by European powers, as nations such as Spain, Portugal, the Netherlands, England, and France sought new routes and territories for trade and expansion. This colonization often resulted in the exploitation of local populations and resources. In addition to colonization, there was substantial contact and cultural exchange facilitated by the region's active maritime trade, which was carried on from India to Southeast Asia and beyond. Furthermore, the arrival of Islam with the invasions and migrations of Turkic and Arab peoples introduced a significant cultural and religious diversity to the area, especially with the establishment of the Delhi Sultanate. The spread of Islam did not enforce cultural homogeneity; rather, it added to the complexity of the region's cultural landscape. Finally, the Indian Ocean trade networks continued to thrive, enhancing economic and cultural interactions among diverse communities in the region.
In summary, the three major changes in the Indian Ocean region in the 1800s were increased European colonization, continued cultural exchanges through thriving trade networks, and an increase in cultural and religious diversity, particularly with the spread of Islam.