Short answers, pulled from the story.
Giotto began painting figures that breathed in the year 1305 at the Scrovegni Chapel in Padua. These works broke from flat Italo-Byzantine traditions by introducing weight, volume, and discernible anatomy to Madonna and Child figures.
Masaccio started true Early Renaissance frescos in the year 1425 when he and Masolino began painting the Life of St Peter in the Brancacci Chapel. He used a single vanishing point in his fresco Tribute Money to convey three-dimensional quality through strong contrast between light and dark.
Leonardo da Vinci painted The Last Supper from 1495 to 1498 in the refectory of Santa Maria delle Grazie. This work became the benchmark for religious narrative painting for the next half millennium after its completion.
Michelangelo completed the Sistine Chapel ceiling over nearly five years starting in 1508 when Pope Julius II got him to agree to continue the decorative scheme. The scale of the work required single-handed effort except for manual assistance during this period.
Raphael died at age thirty-seven just one year after Leonardo da Vinci passed away. His name is synonymous with the High Renaissance though he was younger than Michelangelo by eighteen years and Leonardo by almost thirty.
Titian became monarch of the Venetian School for over sixty years following Giorgione's death in 1510. He applied colors paste-like in patches alongside each other with loose sweeping brush strokes bringing out light and color equally throughout his career.