Question: Sir Andrew Dudley commanded the English garrison of castle on the banks of what river?

Context paragraphs:
Orwell, Prince Edward Island: Canadian professor, physician, and intellectual Sir Andrew Macphail was born in Orwell on November 24, 1864.  The Sir Andrew Macphail Foundation preserves his family home and its 140-acre property in Orwell as a museum, the Sir Andrew Macphail Homestead.  The Homestead is the site of the Macphail Woods Ecological Forestry Project, a joint effort of the Foundation and the Environmental Coalition of Prince Edward Island to preserve the old-growth Acadian Forest covering much of the property.

Roughan Castle: Roughan Castle is a castle a mile outside Newmills, County Tyrone, Northern Ireland, on the Dungannon to Stewartstown road.  It was built about 1618 by Sir Andrew Stewart (d.1639), 2nd Lord Castlestewart, eldest son of Andrew Stewart (1580-1629) the third Lord Ochiltree, 1st Lord Castlestewart who came from Scotland during the plantation and established the nearby town of Stewartstown.  Andrew Stewart junior acquired the land of Ballokevan from Robert Stewart between 1610 and 1619 and built his castle overlooking Roughan Lough.  It is a small square castle, three storeys high with a central tower 20 ft square, flanked by thick rounded towers at each corner.

Siege of Frankenthal: The Siege of Frankenthal was a siege of the Palatinate campaign during the Thirty Years' War.  A Spanish army under Gonzalo Fernández de Córdoba besieged the city and its mostly English garrison commanded by Horace Vere.  The siege lasted from 1621 to March 20, 1623, when King James I ordered the city to surrender.

Sir Andrew Aguecheek: Sir Andrew Aguecheek (also spelled Ague-cheek) is a comic character in William Shakespeare's play "Twelfth Night, or What You Will".  One of the minor characters, Sir Andrew is a stereotypical fool, who is goaded into unwisely duelling with Cesario and who is slowly having his money pilfered by Sir Toby Belch.  He is dim-witted, vain and clownish.  His role in the play not only provides comedy through his pathetic situation and his long speech, but also by his distinct, long-faced appearance and garish dress sense.  The role has been a favourite for noted actors such as Alec Guinness, Christopher Plummer, Paul Scofield and Roger Rees.

Siege of Sluis (1587): The Siege of Sluis of 1587 took place between 12 June and 4 August 1587, as part of the Eighty Years' War and the Anglo-Spanish War (1585–1604).  On 12 June 1587, Don Alexander Farnese, Duke of Parma "(Spanish: Alejandro Farnesio)", Governor-General of the Spanish Netherlands, and commander-in-chief of the Army of Flanders, laid siege to the strategic deep-water port of Sluis, defended by English and Dutch troops under Sir Robert Dudley, Earl of Leicester, Governor-General of the United Provinces, and Sir Roger Williams.  On 24 June, the bombardment began, and on 4 August, after of 13 days of constant fighting around the walls, the English garrison surrendered. <ref name="Parker/Martin p. 126–127">Parker/Martin p. 126–127</ref> The loss of the English-held port of Sluis revealed the inability of Leicester to assert his authority over the Dutch allies, who refused to cooperate in relieving the town, and led to recriminations between the governor-general and the States of Holland.

Andrew Dudley: Sir Andrew Dudley, KG (c. 1507 – 1559) was an English soldier, courtier, and diplomat.  A younger brother of John Dudley, 1st Duke of Northumberland, he served in Henry VIII's navy and obtained court offices under Edward VI.  In 1547–1548 he acted as admiral of the fleet and participated in the War of the Rough Wooing in Scotland, where he commanded the English garrison of Broughty Castle.  He was appointed captain of the fortress of Guînes in the Pale of Calais in late 1551.  There he got involved in a dispute with the Lord Deputy of Calais, which ended only when both men were replaced in October 1552.

Ardrossan Castle: Ardrossan Castle is situated on the west coast of Scotland in the town of Ardrossan, Ayrshire.  The castle, defended by a moat, stands on a ridge above the town.  There is a keep dating from the fifteenth century, and a vaulted range containing a kitchen and cellars.  In a deep passageway there is a well.  Part of the keep remains up to the corbels of the parapet, but it is in ruins.  The original castle, owned by Clan Barclay, was partly destroyed during the Wars of Scottish Independence.  This event, in which the English garrison were slaughtered, became known as "Wallace's Larder," a name which is still applied to the remaining vaults.  Rebuilt by Clan Montgomery in the 15th century, Ardrossan later fell into disuse and was partially demolished by the soldiers of Oliver Cromwell in the 17th century who used the stones to help construct the Ayr Citadel.

Andrew Murray (Scottish soldier): Sir Andrew Murray (1298–1338), also known as Sir Andrew Moray, or Sir Andrew de Moray, was a Scottish military and political leader who supported David II of Scotland against Edward Balliol and King Edward III of England during the so-called Second War of Scottish Independence.  He held the lordships of Avoch and Petty in north Scotland, and Bothwell in west-central Scotland.  In 1326 he married Christina Bruce, a sister of King Robert I of Scotland.  Murray was twice chosen as Guardian of Scotland, first in 1332, and again from 1335 on his return to Scotland after his release from captivity in England.  He held the guardianship until his death in 1338.

Sir Andrew de Leslie II: Sir Andrew de Leslie II, eldest son of Sir Andrew de Leslie I, by his wife Mary Abernethy, succeeded his father as head of the Leslie Family.  before 1325, and appears to have died before 1353, leaving his son also called Sir Andrew as his successor.

Broughty Castle: Broughty Castle is a historic castle on the banks of the river Tay in Broughty Ferry, Dundee, Scotland.  It was completed around 1495, although the site was earlier fortified in 1454 when George Douglas, 4th Earl of Angus received permission to build on the site.  His son Archibald Douglas, 5th Earl of Angus was coerced into ceding the castle to the crown.  The main tower house forming the centre of the castle with four floors was built by Andrew, 2nd Lord Gray who was granted the castle in 1490.

Supporting paragraphs: Andrew Dudley Broughty Castle
Answer: the river Tay