diff --git a/frontend/src/components/gallery/TimelineSidebar.vue b/frontend/src/components/gallery/TimelineSidebar.vue
new file mode 100644
index 0000000..8ea5c24
--- /dev/null
+++ b/frontend/src/components/gallery/TimelineSidebar.vue
@@ -0,0 +1,88 @@
+<template>
+  <aside class="fc-timeline" aria-label="Gallery timeline">
+    <h3 class="fc-timeline__title">Timeline</h3>
+    <ul v-if="!store.timelineLoading" class="fc-timeline__list">
+      <li v-for="group in grouped" :key="group.year">
+        <div class="fc-timeline__year">{{ group.year }}</div>
+        <ul class="fc-timeline__months">
+          <li v-for="bucket in group.buckets" :key="`${bucket.year}-${bucket.month}`">
+            <button class="fc-timeline__bucket" @click="store.jumpTo(bucket.year, bucket.month)">
+              <span class="fc-timeline__month">{{ monthShort(bucket.month) }}</span>
+              <span class="fc-timeline__count">{{ bucket.count }}</span>
+            </button>
+          </li>
+        </ul>
+      </li>
+    </ul>
+    <div v-else class="text-caption">Loading…</div>
+  </aside>
+</template>
+
+<script setup>
+import { computed, onMounted } from 'vue'
+import { useGalleryStore } from '../../stores/gallery.js'
+
+const store = useGalleryStore()
+onMounted(() => store.loadTimeline())
+
+const MONTHS_SHORT = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+                       'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
+function monthShort(m) { return MONTHS_SHORT[m - 1] }
+
+const grouped = computed(() => {
+  const out = []
+  let current = null
+  for (const b of store.timelineBuckets) {
+    if (!current || current.year !== b.year) {
+      current = { year: b.year, buckets: [] }
+      out.push(current)
+    }
+    current.buckets.push(b)
+  }
+  return out
+})
+</script>
+
+<style scoped>
+.fc-timeline {
+  position: sticky;
+  top: 16px;
+  width: 160px;
+  max-height: calc(100vh - 96px);
+  overflow-y: auto;
+  padding: 12px;
+  background: rgb(var(--v-theme-surface));
+  border-radius: 8px;
+  border: 1px solid rgb(var(--v-theme-surface-light));
+}
+.fc-timeline__title {
+  font-family: 'Fraunces', Georgia, serif;
+  font-size: 14px;
+  text-transform: uppercase;
+  letter-spacing: 0.05em;
+  font-weight: 500;
+  color: rgb(var(--v-theme-on-surface));
+  margin-bottom: 8px;
+}
+.fc-timeline__list { list-style: none; padding: 0; margin: 0; }
+.fc-timeline__year {
+  font-family: 'Fraunces', Georgia, serif;
+  font-size: 16px;
+  font-weight: 500;
+  color: rgb(var(--v-theme-accent));
+  margin: 12px 0 4px;
+}
+.fc-timeline__months { list-style: none; padding: 0; margin: 0; }
+.fc-timeline__bucket {
+  display: flex; justify-content: space-between; width: 100%;
+  padding: 4px 6px;
+  background: transparent; border: none; color: rgb(var(--v-theme-on-surface));
+  font: inherit; cursor: pointer; border-radius: 4px;
+  transition: background 100ms ease;
+}
+.fc-timeline__bucket:hover { background: rgb(var(--v-theme-surface-light)); }
+.fc-timeline__count {
+  color: rgb(var(--v-theme-on-surface-variant, var(--v-theme-on-surface)));
+  font-size: 12px;
+}
+</style>
diff --git a/frontend/src/components/modal/ImageViewer.vue b/frontend/src/components/modal/ImageViewer.vue
new file mode 100644
index 0000000..370b462
--- /dev/null
+++ b/frontend/src/components/modal/ImageViewer.vue
@@ -0,0 +1,9 @@
+<template>
+  <v-dialog :model-value="true" max-width="600" @update:model-value="$emit('close')">
+    <v-card>
+      <v-card-title>Image viewer</v-card-title>
+      <v-card-text>Modal viewer lands in Batch 5 (Tasks 19–22).</v-card-text>
+    </v-card>
+  </v-dialog>
+</template>
+<script setup>defineEmits(['close'])</script>
diff --git a/frontend/src/router.js b/frontend/src/router.js
index c983d82..fab0176 100644
--- a/frontend/src/router.js
+++ b/frontend/src/router.js
@@ -1,10 +1,11 @@
 import { createRouter, createWebHistory } from 'vue-router'
 import PlaceholderView from './views/PlaceholderView.vue'
 import SettingsView from './views/SettingsView.vue'
+import GalleryView from './views/GalleryView.vue'
 
 const routes = [
   // FC-2: image backbone
-  { path: '/',          name: 'gallery',       component: PlaceholderView, meta: { title: 'Gallery'      } },
+  { path: '/',          name: 'gallery',       component: GalleryView,    meta: { title: 'Gallery'      } },
   { path: '/showcase',  name: 'showcase',      component: PlaceholderView, meta: { title: 'Showcase'     } },
   { path: '/tags',      name: 'tags',          component: PlaceholderView, meta: { title: 'Tags'         } },
   { path: '/settings',  name: 'settings',      component: SettingsView,    meta: { title: 'Settings'     } },
diff --git a/frontend/src/stores/modal.js b/frontend/src/stores/modal.js
new file mode 100644
index 0000000..7f88020
--- /dev/null
+++ b/frontend/src/stores/modal.js
@@ -0,0 +1,10 @@
+import { defineStore } from 'pinia'
+import { ref } from 'vue'
+
+// Placeholder modal store — real implementation lands in Task 19.
+export const useModalStore = defineStore('modal', () => {
+  const currentImageId = ref(null)
+  function open(id) { currentImageId.value = id }
+  function close() { currentImageId.value = null }
+  return { currentImageId, open, close }
+})
diff --git a/frontend/src/views/GalleryView.vue b/frontend/src/views/GalleryView.vue
new file mode 100644
index 0000000..c2f9d72
--- /dev/null
+++ b/frontend/src/views/GalleryView.vue
@@ -0,0 +1,77 @@
+<template>
+  <v-container fluid class="py-6">
+    <h1 class="fc-h1 mb-4">Gallery</h1>
+    <div class="fc-gallery-layout">
+      <div class="fc-gallery-layout__main">
+        <EmptyState v-if="store.isEmpty" />
+        <GalleryGrid v-else @open="openImage" />
+      </div>
+      <TimelineSidebar v-if="store.images.length > 0" class="fc-gallery-layout__sidebar" />
+    </div>
+
+    <ImageViewer
+      v-if="modal.currentImageId !== null"
+      @close="closeImage"
+    />
+  </v-container>
+</template>
+
+<script setup>
+import { onMounted, watch } from 'vue'
+import { useRoute, useRouter } from 'vue-router'
+import { useGalleryStore } from '../stores/gallery.js'
+import { useModalStore } from '../stores/modal.js'
+import GalleryGrid from '../components/gallery/GalleryGrid.vue'
+import TimelineSidebar from '../components/gallery/TimelineSidebar.vue'
+import EmptyState from '../components/gallery/EmptyState.vue'
+import ImageViewer from '../components/modal/ImageViewer.vue'
+
+const store = useGalleryStore()
+const modal = useModalStore()
+const router = useRouter()
+const route = useRoute()
+
+onMounted(async () => {
+  await store.loadInitial()
+  await store.loadTimeline()
+  // Open modal if URL has ?image=N
+  const initial = parseInt(route.query.image, 10)
+  if (!isNaN(initial)) modal.open(initial)
+})
+
+watch(() => route.query.image, (q) => {
+  const id = parseInt(q, 10)
+  if (!isNaN(id) && id !== modal.currentImageId) modal.open(id)
+  else if (isNaN(id) && modal.currentImageId !== null) modal.close()
+})
+
+function openImage(id) {
+  router.push({ query: { ...route.query, image: id } })
+}
+function closeImage() {
+  const q = { ...route.query }
+  delete q.image
+  router.push({ query: q })
+}
+</script>
+
+<style scoped>
+.fc-h1 {
+  font-family: 'Fraunces', Georgia, serif;
+  font-size: 32px;
+  font-weight: 500;
+  color: rgb(var(--v-theme-on-surface));
+}
+.fc-gallery-layout {
+  display: flex;
+  gap: 16px;
+  align-items: flex-start;
+}
+.fc-gallery-layout__main { flex: 1; min-width: 0; }
+.fc-gallery-layout__sidebar { flex-shrink: 0; }
+
+@media (max-width: 900px) {
+  .fc-gallery-layout { flex-direction: column-reverse; }
+  .fc-gallery-layout__sidebar { width: 100%; max-height: 200px; }
+}
+</style>