Abbot and Sir Ralph in this question are the characters in the poem "the Inchcape Rock".
The Abbot of Aberbrothok was a gentle soul. He tied a bell on the Inchcape Rock because it is dangerous to passing ships. The ringing bell on the Inchcape Rock acts as a warning device to passing ships and letting them know that they have to veer far from the perilous rock or risk crashing their ship on the rocks and sinking it. Because of his initiative, many seafarers were saved and they give praises to him.
Sir Ralph, a pirate, was jealous of the fame and good will the Abbot received and he wanted to discredit the Abbot. He, then, removed the bell from the Inchcape Rock and waited for a ship to face the peril. Unfortunately, it was his ship that crashed on the rock and he died.