On 25th March 1349 [his father] John Mowbray 4th Baron Mowbray Baron Segrave and [his mother] Elizabeth Segrave 5th Baroness Segrave Baroness Mowbray were married. She by marriage Baroness Mowbray. He by marriage Baron Segrave. She the daughter of [his grandfather] John Segrave 4th Baron Segrave and [his grandmother] Margaret Plantagenet 1st Duchess of Norfolk.
On 1st August 1365 John Mowbray 1st Earl Nottingham was born to John Mowbray 4th Baron Mowbray Baron Segrave and Elizabeth Segrave 5th Baroness Segrave Baroness Mowbray.
Before 1368 [his mother] Elizabeth Segrave 5th Baroness Segrave Baroness Mowbray died. John Mowbray 1st Earl Nottingham succeeded 6th Baron Segrave. The date somewhat uncertain but consistent with John Mowbray 1st Earl Nottingham succeeding.
In 1368 [his father] John Mowbray 4th Baron Mowbray Baron Segrave died at Constantinople aka Istanbul, Turkey. John Mowbray 1st Earl Nottingham succeeded 5th Baron Mowbray.
On 16th July 1377 King Richard II of England was crowned II King of England at Westminster Abbey by Archbishop Simon Sudbury.
Richard Fitzalan 9th Earl of Surrey 4th or 11th Earl of Arundel carried the Crown.
Guichard d'Angle 1st Earl Huntingdon was created 1st Earl Huntingdon for life.
John Mowbray 1st Earl Nottingham was created 1st Earl Nottingham.
Edward 2nd Duke of York 1st Duke Albemarle and Robert Harrington 3rd Baron Harington were knighted.
Roger Scales 4th Baron Scales attended.
Westminster Chronicle. On the night immediately following the feast of Saint Scholastica the Virgin [10th February 1383], the earl of Nottingham1, aged twenty years, ended his life and received burial among the Carmelite friars. In the month of February, the abbot of Battle died. After the mysteries of the Mass had been completed, while he was saying the Gospel, "In the beginning", and had come to the place where it says, "And the Word was made flesh", he was struck by sickness near the heart and cried out, "Lord, have mercy on me." The ministers ran to him and tried to comfort him, but, when they could do nothing in this, they laid him on his bed, where at once, the anguish of pain prevailing, he left his body without spirit. At his death very many felt the deepest sorrow. For, beneath the habit of a monk, he had been a distinguished warrior, most vigorously guarding the country, its neighbours, and the sea-coasts from the invasions of pirates. He was succeeded by Sir John Craneforde, a monk of the same monastery.
Nocte sequente immediate festum Scolastieæ virginis comes de Notyngham ætate xx. annorum vitam terminavit et apud fratres Carmelitas sepulturam possedit. De mense Februario, obiit abbas de Bello. Hic missarum peractis mysteriis dum diceret illud evangelium In primcipio, et pervenisset ad illud ubi dicitur Æt verbum caro factum est, juxta cor languore percussus clamitabat "Domine, Miserere mei." Unde accurrentes ministri eum confortare nitebantur, sed dum nil in hoc valerent in stratu suo eum reposuerunt, ubi statim, doloris angustia prævalente, corpus sine spiritu reliquit. De cujus morte plurimi summum mœrorem trahebant. Fuerat enim sub habitu monachico belliger insignis patriam et conterminos littoraque maris ab invasionibus piratarum strenuissime servans. Huic successit dominus Johannes Craneforde monachus ejusdem monasterii.
Note 1. John Mowbray, 1365-1383, son of John Mowbray, 4th Baron Mowbray, and Elizabeth Segrave. By his mother he was a 2 x great grandson of King Edward I. He and King Richard II were second cousins once removed. Mowbray was created Earl of Nottingham aged eleven at the Coronation of King Richard II in 1377.
On 10th February 1383 John Mowbray 1st Earl Nottingham died. He was buried at Whitefriars. Earl Nottingham extinct. [his brother] Thomas Mowbray 1st Duke of Norfolk succeeded 6th Baron Mowbray, 7th Baron Segrave.
Westminster Chronicle. On the third day of February, the king held a parliament at Westminster, in which Thomas, Duke of Gloucester, Henry, Earl of Derby, Richard, Earl of Arundel, Thomas, Earl of Warwick, and Thomas, Earl of Nottingham publicly excused themselves before the whole parliament, saying that they had never consented to, thought of, or imagined the death of the king, either secretly or openly. They declared that they were willing to prove this with their own hands against anyone contradicting them, and to defend themselves in these matters against any opponent who had a head, the king alone excepted. And since no contradictor appeared in response to this, they were considered by all to have been cleared.
Tertio die Februarii tenuit rex parliamentum apud Westmonasterium in quo Thomas dux Gloucestriæ, Henricus comes Derbeye, Ricardus comes Arundelliæ, Thomas comes Warwyk, et Thomas comes Notyngham exeusarunt se publice coram toto parliamento quod nunquam consenserunt cogitarunt aut imaginarunt mortem regis neque occulte neque aperte et hoc cuilibet contradicenti manu propria vellent probare et se de his defendere contra quemlibet opponentem caput habentem rege solo excepto. Cumque ad hæc nullus apparuit contradictor pro excusatis ab omnibus habebantur.