diff --git a/kitty/boss.py b/kitty/boss.py
index 1c4d95454..a94d8ba30 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -6,20 +6,29 @@ from collections import deque
 
 from PyQt5.QtCore import QObject
 
+from .data_types import Line, rewrap_lines
 from .term import TerminalWidget
 
+
 class Boss(QObject):
 
     def __init__(self, opts, parent=None):
+        QObject.__init__(self, parent)
         self.linebuf = deque(maxlen=max(1000, opts.scrollback_lines))
         self.term = TerminalWidget(opts, self.linebuf, parent)
         self.term.relayout_lines.connect(self.relayout_lines)
 
     def apply_opts(self, opts):
         if opts.scrollback_lines != self.linebuf.maxlen:
-            self.linebuf, old = deque(maxlen=max(1000, opts.scrollback_lines)), self.linebuf
-            self.linebuf.extend(old)
+            self.linebuf = deque(self.linebuf, maxlen=max(1000, opts.scrollback_lines))
+            self.term.linebuf = self.linebuf
         self.term.apply_opts(opts)
 
-    def relayout_lines(self):
-        pass
+    def relayout_lines(self, previous, cells_per_line):
+        if previous == cells_per_line:
+            return
+        old = self.linebuf.copy()
+        print(list(old))
+        self.linebuf.clear()
+        self.linebuf.extend(rewrap_lines(old, cells_per_line))
+        print(list(self.linebuf))
diff --git a/kitty/data_types.py b/kitty/data_types.py
index 66bb8642d..6a0847cda 100644
--- a/kitty/data_types.py
+++ b/kitty/data_types.py
@@ -2,7 +2,7 @@
 # vim:fileencoding=utf-8
 # License: GPL v3 Copyright: 2016, Kovid Goyal <kovid at kovidgoyal.net>
 
-from typing import Tuple, Dict, Union
+from typing import Tuple, Dict, Union, Iterator, Sequence
 
 from numpy import zeros, dtype
 from PyQt5.QtGui import QColor
@@ -12,7 +12,7 @@ color_type = dtype([('type', 'u1'), ('r', 'u1'), ('g', 'u1'), ('b', 'u1')])
 
 class Line:
 
-    __slots__ = 'char fg bg bold italic reverse strikethrough decoration decoration_fg'.split()
+    __slots__ = 'char fg bg bold italic reverse strikethrough decoration decoration_fg width'.split()
     continued = False
 
     def __init__(self, sz: int):
@@ -25,6 +25,25 @@ class Line:
         self.strikethrough = zeros(sz, bool)
         self.decoration = zeros(sz, 'u1')
         self.decoration_fg = zeros(sz, color_type)
+        self.width = zeros(sz, 'u1')
+
+    def __len__(self):
+        return len(self.char)
+
+    def copy_char(self, src: int, to, dest: int) -> None:
+        to.char[dest] = self.char[src]
+        to.fg[dest] = self.fg[src]
+        to.bg[dest] = self.bg[src]
+        to.bold[dest] = self.bold[src]
+        to.italic[dest] = self.italic[src]
+        to.reverse[dest] = self.reverse[src]
+        to.strikethrough[dest] = self.strikethrough[src]
+        to.decoration[dest] = self.decoration[src]
+        to.decoration_fg[dest] = self.decoration_fg[src]
+        to.width[dest] = self.width[src]
+
+    def __repr__(self) -> str:
+        return repr(''.join(self.char))
 
 
 def as_color(entry: Tuple[int, int, int, int], color_table: Dict[int, QColor]) -> Union[QColor, None]:
@@ -33,3 +52,38 @@ def as_color(entry: Tuple[int, int, int, int], color_table: Dict[int, QColor]) -
         return color_table.get(r)
     if t == 2:
         return QColor(r, g, b)
+
+
+def copy_char(src: Line, dest: Line, src_pos: int, dest_pos: int) -> None:
+    for i in range(src.width[src_pos]):
+        src.copy_char(src_pos + i, dest, dest_pos + i)
+
+
+def rewrap_lines(lines: Sequence[Line], width: int) -> Iterator[Line]:
+    if lines:
+        current_line, current_dest_pos = Line(width), 0
+        src_limit = len(lines[0]) - 1
+        for i, src in enumerate(lines):
+            current_src_pos = 0
+            while current_src_pos <= src_limit:
+                cw = src.width[current_src_pos]
+                if cw == 0:
+                    # Hard line break, start a new line
+                    yield current_line
+                    current_line, current_dest_pos = Line(width), 0
+                    break
+                if cw + current_dest_pos > width:
+                    # dest line does not have enough space to hold the current source char
+                    yield current_line
+                    current_line, current_dest_pos = Line(width), 0
+                    current_line.continued = True
+                copy_char(src, current_line, current_src_pos, current_dest_pos)
+                current_dest_pos += cw
+                current_src_pos += cw
+            else:
+                hard_break = src is not lines[-1] and not lines[i + 1].continued
+                if hard_break:
+                    yield current_line
+                    current_line, current_dest_pos = Line(width), 0
+        if current_dest_pos:
+            yield current_line