Short answers, pulled from the story.
Grammar schools were originally established to teach Latin to boys destined for the church. The earliest examples, such as the King's School, Canterbury, founded in 597 AD, were attached to cathedrals and monasteries. Latin was the language of religious administration, and fluency in it was required for priesthood and access to the ancient universities.
The Tripartite System was England and Wales's first nationwide state-funded secondary education structure, created by the Education Act 1944. Grammar schools formed one of its three tiers, designed to educate the most academically able 25 percent of pupils as selected by the eleven-plus examination. At their peak in 1964, there were 1,298 state-maintained grammar schools in England and Wales.
England currently has 163 fully selective state-funded grammar schools, out of approximately 3,000 state secondaries in total. Northern Ireland has 69 remaining grammar schools, and by 2006 they were taking 42 percent of all transferring children.
The Direct Grant Grammar Schools (Cessation of Grant) Regulations 1975 required direct-grant schools to either convert to comprehensives under local authority control or become fully independent fee-paying schools. Of those remaining at the time, 51 became comprehensive, 119 opted for independence, and five were expected to become independent or close.
The only ballot held to date on ending selection at an English grammar school took place for Ripon Grammar School in 2000. Parents rejected the change by a ratio of 2 to 1. A 2004 Select Committee for Education and Skills report condemned the ballot arrangements as ineffective and a waste of time and resources.
In Australia, independent grammar schools were established in the mid-19th century, mostly attached to the Church of England, to spare wealthy families from sending sons to Britain. Queensland's Grammar Schools Act 1860 funded non-denominational grammar schools, beginning with Ipswich Grammar School in 1863. In New Zealand, Auckland Grammar School was established in 1850 and formally recognised in 1868; today all New Zealand grammar schools are non-selective state schools.