Wikipedia
Ahimelech (Hebrew: אחימלך "the [divine] king is brother"), the son of Ahitub and father of Abiathar (1 Sam. 22:20-23), described in 2 Sam. 8:17 as the son of Abiathar and in four places in 1 Chronicles. He descended from Aaron's son Ithamar and the high priest Eli. In 1 Chr. 18:16 his name is Abimelech according to the Masoretic Text, and is probably the same as Ahiah (1 Sam. 14:3, 18). He was the twelfth High Priest, and officiated at Nob, where he was visited by David (to whom and his companions he gave five loaves of the showbread) when David fled from Saul (1 Sam. 21:1-9). He was summoned into Saul's presence, and accused, on the information of Doeg the Edomite, of disloyalty because of his kindness to David; whereupon the king commanded that he, with the other priests who stood beside him, 86 in all, should be slain with his family. This sentence was carried into execution by Doeg in the most cruel manner (1 Sam. 22:9-23). Possibly Abiathar had a son also called Ahimelech, or the two names, as some think, may have been accidentally transposed in 2 Sam. 8:17; 1 Chr. 18:16, marg.; 24:3, 6, 31.
Ahimelech's death was seen as a partial fulfilment of the curse on the House of Eli – that none of Eli's male descendants would live to old age; the other part of the curse on the House of Eli – that the priesthood would pass out of his descendants – was fulfilled when Abiathar was deposed from the office of High Priest. Rabbinical literature linked the extermination of the male descendants of David with the extermination of the priests of Nob by Saul - deeming it divine retribution because David's action had provoked Saul's outburst - and also linked the survival of David's descendant Joash with that of Ahimelech's son Abiathar.