Sir Oliver horse came

“Sir Oliver’s horse came ambling home to Oliver’s abode”

I’ve been carrying that phrase around in my head for… a long time. Since Mrs Wilson, my secondary school maths teacher, put it in our heads as a mnemonic for remembering how sin, cos and tan are based on the ratios of the sides of triangles (scream if you want to go nerdier). Anyway, these last couple of days, for no obvious reason, I started wondering about the following meaningless questions:
Who was Oliver? How did he get his knighthood? What had he been doing to lose his faithful horse? Did it involve trigonometry? Maybe there’s a story there.