King Charles III shook hands and chatted with onlookers after attending an Easter service at Windsor Castle on Sunday in his most significant public outing since being diagnosed with cancer last month.

The king, dressed in a dark overcoat and shiny blue tie, smiled as he made his way along a rope line outside St. George’s Chapel for about five minutes, reaching into the crowd to greet supporters who waved get-well cards and snapped photos on a chilly early spring day. “You’re very brave to stand out here in the cold,” Charles told them.