diff --git a/src/Types/Events.ts b/src/Types/Events.ts
index d97320c0..96a14096 100644
--- a/src/Types/Events.ts
+++ b/src/Types/Events.ts
@@ -27,6 +27,8 @@ export type BaileysEventMap = {
 		chats: Chat[]
 		contacts: Contact[]
 		messages: WAMessage[]
+		/** Past participants for group chats (people who left/were removed). userJid is always a phone number (PN), never a LID. */
+		pastParticipants?: proto.IPastParticipants[] | null
 		isLatest?: boolean
 		progress?: number | null
 		syncType?: proto.HistorySync.HistorySyncType | null
@@ -185,6 +187,8 @@ export type BufferedEventData = {
 		chats: { [jid: string]: Chat }
 		contacts: { [jid: string]: Contact }
 		messages: { [uqId: string]: WAMessage }
+		/** Keyed by groupJid for O(1) deduplication across chunks */
+		pastParticipants: { [groupJid: string]: proto.IPastParticipant[] }
 		empty: boolean
 		isLatest: boolean
 		progress?: number | null
diff --git a/src/Utils/event-buffer.ts b/src/Utils/event-buffer.ts
index 1b19a3e8..027d8798 100644
--- a/src/Utils/event-buffer.ts
+++ b/src/Utils/event-buffer.ts
@@ -1,4 +1,5 @@
 import EventEmitter from 'events'
+import { proto } from '../../WAProto/index.js'
 import type {
 	BaileysEvent,
 	BaileysEventEmitter,
@@ -890,6 +891,7 @@ const makeBufferData = (): BufferedEventData => {
 			chats: {},
 			messages: {},
 			contacts: {},
+			pastParticipants: {},
 			isLatest: false,
 			empty: true
 		},
@@ -967,6 +969,28 @@ function append<E extends BufferableEvent>(
 				}
 			}
 
+			// Merge pastParticipants with deduplication by groupJid and by userJid within each group.
+			// Multiple HistorySync chunks can carry the same group -- we merge rather than concatenate
+			// to avoid duplicate entries in the final event delivered to the consumer.
+			for (const group of (eventData.pastParticipants ?? []) as proto.IPastParticipants[]) {
+				const groupJid = group.groupJid
+				if (!groupJid) continue
+
+				if (!data.historySets.pastParticipants[groupJid]) {
+					data.historySets.pastParticipants[groupJid] = []
+				}
+
+				const existing = data.historySets.pastParticipants[groupJid]
+				const seenJids = new Set(existing.map(p => p.userJid).filter(Boolean))
+
+				for (const participant of (group.pastParticipants ?? []) as proto.IPastParticipant[]) {
+					if (participant.userJid && !seenJids.has(participant.userJid)) {
+						existing.push(participant)
+						seenJids.add(participant.userJid)
+					}
+				}
+			}
+
 			data.historySets.empty = false
 			data.historySets.syncType = eventData.syncType
 			data.historySets.progress = eventData.progress
@@ -1292,6 +1316,10 @@ function consolidateEvents(data: BufferedEventData) {
 			chats: Object.values(data.historySets.chats),
 			messages: Object.values(data.historySets.messages),
 			contacts: Object.values(data.historySets.contacts),
+			// Convert dedup map back to array. Each entry has groupJid + participants (all unique userJids).
+			pastParticipants: Object.entries(data.historySets.pastParticipants).map(
+				([groupJid, participants]) => ({ groupJid, pastParticipants: participants })
+			),
 			syncType: data.historySets.syncType,
 			progress: data.historySets.progress,
 			isLatest: data.historySets.isLatest,
diff --git a/src/Utils/history.ts b/src/Utils/history.ts
index 6442abf2..58ff7bb4 100644
--- a/src/Utils/history.ts
+++ b/src/Utils/history.ts
@@ -374,10 +374,25 @@ export const processHistoryMessage = (item: proto.IHistorySync, logger?: ILogger
 	// Convert Map back to array for return
 	const lidPnMappings = Array.from(lidPnMap.values())
 
+	// Normalize pastParticipants: resolve LID userJids → PN so the consumer always
+	// receives a phone number, never an opaque LID identifier.
+	// Uses the lidPnMap built above (populated from phoneNumberToLidMappings + conversations).
+	// If a LID cannot be resolved, the original value is kept rather than dropping the participant.
+	const pastParticipants: proto.IPastParticipants[] = (item.pastParticipants ?? []).map(group => ({
+		groupJid: group.groupJid,
+		pastParticipants: (group.pastParticipants ?? []).map(participant => {
+			const userJid = participant.userJid
+			if (!userJid || !isAnyLidUser(userJid)) return participant
+			const mapping = lidPnMap.get(jidNormalizedUser(userJid))
+			return mapping?.pn ? { ...participant, userJid: mapping.pn } : participant
+		})
+	}))
+
 	return {
 		chats,
 		contacts,
 		messages,
+		pastParticipants,
 		lidPnMappings,
 		syncType: item.syncType,
 		progress: item.progress