Short answers, pulled from the story.
The Iceni were an ancient tribe of eastern Britain who lived in what is now Norfolk, parts of Suffolk, and Cambridgeshire during the Iron Age and early Roman era. They were a significant power in eastern Britain and initially allied with Rome following the Claudian conquest of AD 43, remaining nominally independent under their king Prasutagus until around AD 60.
Venta Icenorum, located near the modern village of Caistor St. Edmund about 8 kilometres south of present-day Norwich, served as the Iceni capital during the Roman period. The site sits approximately 2 kilometres from the Bronze Age Henge at Arminghall.
After the death of her husband Prasutagus around AD 60, the Romans ignored his will and the procurator Catus Decianus seized the entire Icenian estate. Boudica was flogged and her daughters were raped. Roman financiers also called in their loans at the same time, prompting Boudica to raise the Iceni and the neighbouring Trinovantes in revolt.
Boudica's forces sacked and burned Camulodunum (Colchester), Londinium (London), and Verulamium (St Albans). A Roman source records that two cities were destroyed, eighty thousand Romans and allies were killed, and the island was temporarily lost to Rome.
The Iceni began producing coins around 10 BC. Their coinage adapted the Gallo-Belgic face/horse design, and in some early issues near Norwich, the horse was replaced by a boar. They are the only coin-producing group known to have inscribed their own tribal name on their coins, using the spelling ECENI.
The meaning of Iceni is uncertain. Proposed origins include the Welsh word echen, meaning origin, source, or tribe; the Brittonic word ychen, meaning oxen; and a possible connection to an old name for the River Ouse. The final "-i" is a Latin nominative plural ending. No single etymology has been confirmed.