Short answers, pulled from the story.
The Pallava dynasty ruled from 275 to 897, controlling a significant portion of the Deccan region known as Tondaimandalam. They dominated the southern Telugu region and northern Tamil country for roughly 600 years, with Kanchipuram as their capital.
The Shore Temple at Mamallapuram, built by Narasimhavarman II during his reign from 695 to 722, is the dynasty's most celebrated architectural achievement and is a UNESCO World Heritage Site. The Kailasanatha temple at Kanchipuram is another major example of the mature Pallava style.
The Pallavas used a Brahmic script known as the Pallava script, which gave rise to the Tamil script via the Chozha-Pallava lineage and to Grantha script. Around the 6th century it was exported eastward and influenced the formation of nearly all Southeast Asian scripts, including Khmer.
Mahendravarman I, who reigned from 600 to 630, and his son Narasimhavarman I, who reigned from 630 to 668, brought the Pallavas to the height of their power. Narasimhavarman II, who reigned from 695 to 722, built the Shore Temple at Mamallapuram.
The Pallava dynasty was finally defeated by the Chola ruler Aditya I in the 9th century. Their last king, Vijaya-Nripatungavarman, had held Kanchipuram until that point.
Pallava inscriptions survive in Prakrit, Sanskrit, and Tamil. The earliest records used Prakrit exclusively; Sanskrit became dominant as the dynasty grew; and during the reign of Paramesvaravarman I, bilingual Sanskrit-Tamil inscriptions became standard for copper-plate records.